fixup! buildsystem: introduce global boards makefiles

Author: crasbe

boards/Makefile

@@ -2,7 +2,7 @@
 DIRS += $(RIOTBOARD)/common/init
 
 
-# SORT THIS ALPHABETICALLY BY BOARD NAME!
+# SORT THIS ALPHABETICALLY BY COMMON BOARD NAME!
 ifneq (,$(filter boards_common_adafruit-nrf52-bootloader,$(USEMODULE)))
   DIRS += $(RIOTBOARD)/common/adafruit-nrf52-bootloader
 endif