arm: Use full path in KBUILD_IMAGE definition

The KBUILD_IMAGE variable is used by the rpm and deb-pkg targets, which
expect it to point to the image file in the build directory. The
builddeb script has a workaround for architectures which only provide
the basename, but let's provide a clean interface for packaging tools.

Cc: Russell King <[e-mail]>
Cc: [e-mail]
Signed-off-by: Michal Marek <[e-mail]>
Signed-off-by: Masahiro Yamada <[e-mail]>

arch/arm/Makefile

···
 libs-y				:= arch/arm/lib/ $(libs-y)
 
 # Default target when executing plain make
+boot := arch/arm/boot
 ifeq ($(CONFIG_XIP_KERNEL),y)
-KBUILD_IMAGE := xipImage
+KBUILD_IMAGE := $(boot)/xipImage
 else
-KBUILD_IMAGE := zImage
+KBUILD_IMAGE := $(boot)/zImage
 endif
 
 # Build the DT binary blobs if we have OF configured
···
 KBUILD_DTBS := dtbs
 endif
 
-all:	$(KBUILD_IMAGE) $(KBUILD_DTBS)
+all:	$(notdir $(KBUILD_IMAGE)) $(KBUILD_DTBS)
 
-boot := arch/arm/boot
 
 archheaders:
 	$(Q)$(MAKE) $(build)=arch/arm/tools uapi