change the ?= assignments to =

keyboards/bananasplit/rules.mk

@@ -1,5 +1,5 @@
 # MCU name
-MCU ?= atmega32u4
+MCU = atmega32u4
 
 # Processor frequency.
 #     This will define a symbol, F_CPU, in all source code files equal to the
@@ -12,14 +12,14 @@ MCU ?= atmega32u4
 #     does not *change* the processor frequency - it should merely be updated to
 #     reflect the processor speed set externally so that the code can use accurate
 #     software delays.
-F_CPU ?= 16000000
+F_CPU = 16000000
 
 
 #
 # LUFA specific
 #
 # Target architecture (see library "Board Types" documentation).
-ARCH ?= AVR8
+ARCH = AVR8
 
 # Input clock frequency.
 #     This will define a symbol, F_USB, in all source code files equal to the
@@ -32,7 +32,7 @@ ARCH ?= AVR8
 #
 #     If no clock division is performed on the input clock inside the AVR (via the
 #     CPU clock adjust registers or the clock division fuses), this will be equal to F_CPU.
-F_USB ?= $(F_CPU)
+F_USB = $(F_CPU)
 
 # Interrupt driven control endpoint task(+60)
 OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
@@ -50,14 +50,14 @@ OPT_DEFS += -DBOOTLOADER_SIZE=4096
 # Build Options
 #   comment out to disable the options.
 #
-BOOTMAGIC_ENABLE ?= yes	# Virtual DIP switch configuration(+1000)
-MOUSEKEY_ENABLE ?= yes	# Mouse keys(+4700)
-EXTRAKEY_ENABLE ?= yes	# Audio control and System control(+450)
-CONSOLE_ENABLE ?= yes	# Console for debug(+400)
-COMMAND_ENABLE ?= yes    # Commands for debug and configuration
+BOOTMAGIC_ENABLE = yes	# Virtual DIP switch configuration(+1000)
+MOUSEKEY_ENABLE = yes	# Mouse keys(+4700)
+EXTRAKEY_ENABLE = yes	# Audio control and System control(+450)
+CONSOLE_ENABLE = yes	# Console for debug(+400)
+COMMAND_ENABLE = yes    # Commands for debug and configuration
 #SLEEP_LED_ENABLE = yes  # Breathing sleep LED during USB suspend
-NKRO_ENABLE ?= yes	# USB Nkey Rollover - not yet supported in LUFA
-BACKLIGHT_ENABLE ?= yes
+NKRO_ENABLE = yes	# USB Nkey Rollover - not yet supported in LUFA
+BACKLIGHT_ENABLE = yes
 
 
 # Optimize size but this may cause error "relocation truncated to fit"