kbuild: always use $(CC) for $(call cc-version)

The possibility to specify an optional parameter did not work out as
expected and it was not used - so remove the possibility.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/Kbuild.include

@@ -77,8 +77,7 @@ cc-option-align = $(subst -functions=0,,\
 
 # cc-version
 # Usage gcc-ver := $(call cc-version, $(CC))
-cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh \
-              $(if $(1), $(1), $(CC)))
+cc-version = $(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-version.sh $(CC))
 
 # cc-ifversion
 # Usage:  EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)