ARC: build: remove non-existing bootpImage from KBUILD_IMAGE

The deb-pkg builds for ARCH=arc fail.

  $ export CROSS_COMPILE=<your-arc-compiler-prefix>
  $ make -s ARCH=arc defconfig
  $ make ARCH=arc bindeb-pkg
  SORTTAB vmlinux
  SYSMAP  System.map
  MODPOST Module.symvers
  make KERNELRELEASE=5.10.0-rc4 ARCH=arc KBUILD_BUILD_VERSION=2 -f ./Makefile intdeb-pkg
  sh ./scripts/package/builddeb
  cp: cannot stat 'arch/arc/boot/bootpImage': No such file or directory
  make[4]: *** [scripts/Makefile.package:87: intdeb-pkg] Error 1
  make[3]: *** [Makefile:1527: intdeb-pkg] Error 2
  make[2]: *** [debian/rules:13: binary-arch] Error 2
  dpkg-buildpackage: error: debian/rules binary subprocess returned exit status 2
  make[1]: *** [scripts/Makefile.package:83: bindeb-pkg] Error 2
  make: *** [Makefile:1527: bindeb-pkg] Error 2

The reason is obvious; arch/arc/Makefile sets $(boot)/bootpImage as
the default image, but there is no rule to build it.

Remove the meaningless KBUILD_IMAGE assignment so it will fallback
to the default vmlinux. With this change, you can build the deb package.

I removed the 'bootpImage' target as well. At best, it provides
'make bootpImage' as an alias of 'make vmlinux', but I do not see
much sense in doing so.
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

arch/arc/Makefile

@@ -102,12 +102,6 @@ libs-y		+= arch/arc/lib/ $(LIBGCC)
 
 boot		:= arch/arc/boot
 
-#default target for make without any arguments.
-KBUILD_IMAGE	:= $(boot)/bootpImage
-
-all:	bootpImage
-bootpImage: vmlinux
-
 boot_targets += uImage uImage.bin uImage.gz
 
 $(boot_targets): vmlinux