fixup! cortexm_common: allow defining ROM_OFFFSET in a compilation rule

Author: cladmi

cpu/cortexm_common/Makefile.include

@@ -19,7 +19,7 @@ endif
 # Only define the linker symbol if the variable is set
 # The variable can be set using target specific variable thanks to lazy evaluation
 
-# ROM_OFFSET: offset in rom to start linking, allows using bootloaders
+# ROM_OFFSET: offset in rom to start linking, allows supporting a bootloader
 LINKFLAGS += $(if $(ROM_OFFSET),$(LINKFLAGPREFIX)--defsym=_rom_offset=$(ROM_OFFSET))
 # FW_ROM_LEN: rom length to use for firmware linking. Allows linking only in a section of the rom.
 LINKFLAGS += $(if $(FW_ROM_LEN),$(LINKFLAGPREFIX)--defsym=_fw_rom_length=$(FW_ROM_LEN))