Remove BOOTLOADER_SIZE stuff from template (#8516)

quantum/template/avr/rules.mk

@@ -11,16 +11,6 @@ MCU = atmega32u4
 #   ATmega328P   USBasp
 BOOTLOADER = atmel-dfu
 
-# If you don't know the bootloader type, then you can specify the
-# Boot Section Size in *bytes* by uncommenting out the OPT_DEFS line
-# Otherwise, delete this section
-#   Teensy halfKay      512
-#   Teensy++ halfKay    1024
-#   Atmel DFU loader    4096
-#   LUFA bootloader     4096
-#   USBaspLoader        2048
-# OPT_DEFS += -DBOOTLOADER_SIZE=4096
-
 # Build Options
 #   change yes to no to disable
 #