Add MKS MINI 12864 support for GT2560

Marlin/example_configurations/Geeetech/GT2560/Configuration.h

@@ -1735,7 +1735,7 @@
 /**
  * Customize common displays for GT2560
  */
-#if ENABLED(ULTIMAKERCONTROLLER) || ENABLED(REPRAP_DISCOUNT_SMART_CONTROLLER) || ENABLED(G3D_PANEL)
+#if ENABLED(ULTIMAKERCONTROLLER) || ENABLED(REPRAP_DISCOUNT_SMART_CONTROLLER) || ENABLED(G3D_PANEL) || ENABLED(MKS_MINI_12864)
   #define SDSUPPORT   // Force SD Card support on for these displays
 #elif ENABLED(ULTRA_LCD) && ENABLED(DOGLCD) // No panel, just graphical LCD?
   #define LCD_WIDTH 20 // Default is 22. For this Geeetech use 20

Marlin/pins_GT2560_REV_A.h

@@ -98,6 +98,18 @@
 
   #if ENABLED(NEWPANEL)
 
+  #if ENABLED(MKS_MINI_12864)
+      #define DOGLCD_A0         5
+      #define DOGLCD_CS         21
+
+      #define BTN_EN1           40
+      #define BTN_EN2           42
+      #define BTN_ENC           19
+
+      #define SDSS              53
+      #define SD_DETECT_PIN     38
+  #else
+
       #define LCD_PINS_RS    20
       #define LCD_PINS_ENABLE 17
       #define LCD_PINS_D4    16
@@ -112,6 +124,8 @@
 
       #define SD_DETECT_PIN  38
 
+  #endif
+
   #else // !NEWPANEL
 
     #define SHIFT_CLK      38