Remove unused _BOOTLOADER defines

keyboards/meira/rules.mk

@@ -32,15 +32,14 @@ BOOTLOADER = caterina
 # Interrupt driven control endpoint task(+60)
 OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
 
-
-# Boot Section Size in *bytes*
-#   Teensy halfKay   512
-#   Teensy++ halfKay 1024
-#   Atmel DFU loader 4096
-#   LUFA bootloader  4096
-#   USBaspLoader     2048
-OPT_DEFS += -DBOOTLOADER_SIZE=4096
-
+# Bootloader selection
+#   Teensy       halfkay
+#   Pro Micro    caterina
+#   Atmel DFU    atmel-dfu
+#   LUFA DFU     lufa-dfu
+#   QMK DFU      qmk-dfu
+#   atmega32a    bootloadHID
+BOOTLOADER = caterina
 
 # Build Options
 #   change yes to no to disable