Fix AVR boards which were overriding backlight without setting… (#8044)

* Add backlight custom driver to all boards not declaring it but overriding backlight

* Apply suggestions from code review

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Apply suggestions from code review

Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Remove old tmk references from show_options.mk

Co-authored-by: fauxpark <fauxpark@gmail.com>

keyboards/amj96/rules.mk

@@ -14,7 +14,7 @@ BOOTLOADER = atmel-dfu
 # Build Options
 #   change yes to no to disable
 #
-BOOTMAGIC_ENABLE = no      # Virtual DIP switch configuration
+BOOTMAGIC_ENABLE = no       # Virtual DIP switch configuration
 MOUSEKEY_ENABLE = yes       # Mouse keys
 EXTRAKEY_ENABLE = yes       # Audio control and System control
 CONSOLE_ENABLE = yes        # Console for debug
@@ -22,8 +22,8 @@ COMMAND_ENABLE = no         # Commands for debug and configuration
 # Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 SLEEP_LED_ENABLE = no       # Breathing sleep LED during USB suspend
 # if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
-NKRO_ENABLE ?= yes          # USB Nkey Rollover
-BACKLIGHT_ENABLE = yes      # Enable keyboard backlight functionality on B7 by default
+NKRO_ENABLE = yes           # USB Nkey Rollover
+BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
 RGBLIGHT_ENABLE = yes
 MIDI_ENABLE = no            # MIDI support
 UNICODE_ENABLE = no         # Unicode