Makefile.include: FIX .DEFAULT_GOAL not being all

.DEFAULT_GOAL was reset many times which removed 'all' from being the default
goal.
By chance it was then set to `link` so was working by some magic.

Makefile.include

@@ -1,3 +1,6 @@
+# Globally set default goal to `all`
+.DEFAULT_GOAL := all
+
 # include Makefile.local if it exists
 -include Makefile.local
 

boards/common/frdm/Makefile.include

@@ -26,9 +26,6 @@ export OPENOCD_EXTRA_INIT
 .PHONY: flash
 flash: $(RIOTCPU)/$(CPU)/dist/wdog-disable.bin
 
-# Reset the default goal.
-.DEFAULT_GOAL :=
-
 export OPENOCD_CONFIG ?= $(RIOTBOARD)/common/frdm/dist/old-openocd-$(CPU_FAMILY).cfg
 endif
 

boards/mulle/Makefile.include

@@ -61,9 +61,6 @@ export PRE_FLASH_CHECK_SCRIPT = $(RIOTCPU)/$(CPU)/dist/check-fcfield-elf.sh
 .PHONY: flash
 flash: $(RIOTCPU)/$(CPU)/dist/wdog-disable.bin
 
-# Reset the default goal.
-.DEFAULT_GOAL :=
-
 # this board uses openocd
 include $(RIOTMAKE)/tools/openocd.inc.mk
 

boards/pba-d-01-kw2x/Makefile.include

@@ -15,9 +15,6 @@ PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbmodem*)))
 .PHONY: flash
 flash: $(RIOTCPU)/$(CPU)/dist/wdog-disable.bin
 
-# Reset the default goal.
-.DEFAULT_GOAL :=
-
 # We need special handling of the watchdog if we want to speed up the flash
 # verification by using the MCU to compute the image checksum after flashing.
 # wdog-disable.bin is a precompiled binary which will disable the watchdog and

cpu/kinetis/Makefile.include

@@ -44,7 +44,4 @@ USEMODULE += periph_wdog
 $(RIOTCPU)/$(CPU)/dist/wdog-disable.bin: $(RIOTCPU)/$(CPU)/dist/wdog-disable.s
 	$(Q)$(MAKE) -C $(RIOTCPU)/$(CPU)/dist/ $(notdir $@)
 
-# Reset the default goal to not make wdog-disable.bin the default target.
-.DEFAULT_GOAL :=
-
 include $(RIOTMAKE)/arch/cortexm.inc.mk

makefiles/scan-build.inc.mk

@@ -87,6 +87,3 @@ else
 	    echo "No report found"; \
 	  fi
 endif
-
-# Reset the default goal.
-.DEFAULT_GOAL :=