Makefile: Fix KCONFIG_AUTOHEADER dependencies

This makes the Makefile more robust when changing the file name
or changing the .config outside of make *config

Change-Id: Ifc013cc3ef899a7846742a961261ac50bc67e27b
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: http://review.coreboot.org/10970
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
1 file changed