ramips: move umedia build step to Makefile

Some rt3883 based boards need this one as well.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ramips/image/Makefile

@@ -74,6 +74,10 @@ define MkCombineduImage
 	$(call MkImage,lzma,$(KDIR)/vmlinux-$(2).bin.lzma.combined,$(call sysupname,$(1),$(2)),$(6))
 endef
 
+define Build/umedia-header
+	fix-u-media-header -T 0x46 -B $(1) -i $@ -o $@.new && mv $@.new $@
+endef
+
 #
 # The real magic happens inside these templates
 #

target/linux/ramips/image/mt7620.mk

@@ -26,10 +26,6 @@ define Build/poray-header
 		mv $@.new $@
 endef
 
-define Build/umedia-header
-	fix-u-media-header -T 0x46 -B $(1) -i $@ -o $@.new && mv $@.new $@
-endef
-
 define Build/elecom-header
 	cp $@ $(KDIR)/v_0.0.0.bin
 	( \