Merge pull request #5907 from jfbortolotti/nRF52_linker

cpu: cortexm_common: Remove useless path when setting default value for LINKER_SCRIPT

cpu/Makefile.include.cortexm_common

@@ -16,7 +16,7 @@ export CFLAGS += $(CFLAGS_CPU) $(CFLAGS_LINK) $(CFLAGS_DBG) $(CFLAGS_OPT)
 
 export ASFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG)
 export LINKFLAGS += -L$(RIOTCPU)/$(CPU)/ldscripts -L$(RIOTCPU)/cortexm_common/ldscripts
-export LINKER_SCRIPT ?= $(RIOTCPU)/$(CPU)/ldscripts/$(CPU_MODEL).ld
+export LINKER_SCRIPT ?= $(CPU_MODEL).ld
 export LINKFLAGS += -T$(LINKER_SCRIPT) -Wl,--fatal-warnings
 
 export LINKFLAGS += $(CFLAGS_CPU) $(CFLAGS_DBG) $(CFLAGS_OPT) -static -lgcc -nostartfiles