kbuild: Rename UIMAGE to MKIMAGE

U-Boot uses the 'mkimage' tool to produce various image types,
not only uImage image type. Rename the invocation name from
UIMAGE to MKIMAGE.

The following command was used to do the replacement:
git grep 'quiet_cmd_mkimage.* = UIMAGE' | cut -d : -f 1 | \
 xargs -i sed -i "s@\(quiet_cmd_mkimage\)\(.*\) = UIMAGE @\1\2 = MKIMAGE@" {}

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@ti.com>
Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/board/matrix_vision/mvblm7/Makefile b/board/matrix_vision/mvblm7/Makefile
index b5987fd..9ed2837 100644
--- a/board/matrix_vision/mvblm7/Makefile
+++ b/board/matrix_vision/mvblm7/Makefile
@@ -8,7 +8,7 @@
 
 extra-y := bootscript.img
 
-quiet_cmd_mkimage = UIMAGE  $@
+quiet_cmd_mkimage = MKIMAGE $@
 cmd_mkimage = $(objtree)/tools/mkimage $(MKIMAGEFLAGS_$(@F)) -d $< $@ \
         $(if $(KBUILD_VERBOSE:1=), >/dev/null)
 
diff --git a/board/matrix_vision/mvsmr/Makefile b/board/matrix_vision/mvsmr/Makefile
index fae7ec2..a9c794e 100644
--- a/board/matrix_vision/mvsmr/Makefile
+++ b/board/matrix_vision/mvsmr/Makefile
@@ -12,7 +12,7 @@
 
 extra-y := bootscript.img
 
-quiet_cmd_mkimage = UIMAGE  $@
+quiet_cmd_mkimage = MKIMAGE $@
 cmd_mkimage = $(objtree)/tools/mkimage $(MKIMAGEFLAGS_$(@F)) -d $< $@ \
         $(if $(KBUILD_VERBOSE:1=), >/dev/null)