kbuild: add generic mergeconfig target, %.config

"scripts/kconfig/merge_config.sh && make oldconfig" works well
enough for merging local config fragments, but Kbuild currently has
the entry points only for "kvmconfig" and "tinyconfig".

This commit provides the generic target for mergeconfig, so we can
manage our own config fragments easily:
put "foo.config" in arch/$(SRCARCH)/configs/ or kernel/configs/,
and then run "make foo.config".

Now "make kvmconfig" is just a shorthand of "make kvm_guest.config".
Likewise, "make tinyconfig" is equivalent to
"make allnoconfig tiny.config".

Change-Id: I9ea4fd21ac46b42c2b6d87ee7eeeff67768bc375
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
1 file changed