build: uImage: allow override of default arguments

For some build recipes, the argument to Build/uImage is used to sneak in
extra arguments for mkimage, whereas this appears to have been intended
to specificy the compression method only.

Use the first provided word for -C to be backwards compatible with
current calls to Build/uImage. Use the rest of the call arguments to
override the provided defaults. Only the input file name (-d) and the
output file name cannot overriden.

Signed-off-by: Sander Vanheule <sander@svanheule.net>

include/image-commands.mk

@@ -396,8 +396,9 @@ endef
 define Build/uImage
 	mkimage -A $(LINUX_KARCH) \
 		-O linux -T kernel \
-		-C $(1) -a $(KERNEL_LOADADDR) -e $(if $(KERNEL_ENTRY),$(KERNEL_ENTRY),$(KERNEL_LOADADDR)) \
-		-n '$(if $(UIMAGE_NAME),$(UIMAGE_NAME),$(call toupper,$(LINUX_KARCH)) $(VERSION_DIST) Linux-$(LINUX_VERSION))' -d $@ $@.new
+		-C $(word 1,$(1)) -a $(KERNEL_LOADADDR) -e $(if $(KERNEL_ENTRY),$(KERNEL_ENTRY),$(KERNEL_LOADADDR)) \
+		-n '$(if $(UIMAGE_NAME),$(UIMAGE_NAME),$(call toupper,$(LINUX_KARCH)) $(VERSION_DIST) Linux-$(LINUX_VERSION))' \
+		$(wordlist 2,$(words $(1)),$(1)) -d $@ $@.new
 	mv $@.new $@
 endef