Z_DUAL_ENDSTOP - make offset a configuration item

The offset for Z_DUAL_ENDSTOP (z_endstop_adj) is already in Marlin.
This PR just makes it a configuration item.

z_endstop_adj is initialized in two places so both had to be modified.

Marlin/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine/test this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/configuration_store.cpp

@@ -963,7 +963,11 @@ void Config_ResetDefault() {
     COPY(delta_diagonal_rod_trim, drt);
     COPY(delta_tower_angle_trim, dta);
   #elif ENABLED(Z_DUAL_ENDSTOPS)
-    z_endstop_adj = 0;
+    #if defined(Z_DUAL_ENDSTOPS_ADJUSTMENT)
+      float z_endstop_adj = Z_DUAL_ENDSTOPS_ADJUSTMENT;
+    #else
+      float z_endstop_adj = 0;
+    #endif
   #endif
 
   #if ENABLED(ULTIPANEL)

Marlin/example_configurations/Cartesio/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/Felix/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/Hephestos/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/Hephestos_2/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/K8200/Configuration_adv.h

@@ -298,6 +298,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/K8400/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/RigidBot/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/SCARA/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/TAZ4/Configuration_adv.h

@@ -293,6 +293,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/WITBOX/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/delta/flsun_kossel_mini/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/delta/generic/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/delta/kossel_mini/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/delta/kossel_pro/Configuration_adv.h

@@ -290,6 +290,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/delta/kossel_xl/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/makibox/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS

Marlin/example_configurations/tvrrug/Round2/Configuration_adv.h

@@ -285,6 +285,7 @@
 
   #if ENABLED(Z_DUAL_ENDSTOPS)
     #define Z2_USE_ENDSTOP _XMAX_
+    #define Z_DUAL_ENDSTOPS_ADJUSTMENT  0  // use M666 command to determine this value
   #endif
 
 #endif // Z_DUAL_STEPPER_DRIVERS