coreinfo: Update Makefile

- Get the absolute pathname for LIBPAYLOAD_PATH
- Update distclean:
--correctly remove .config and .config.old - *.config doesn't match
.config
-- remove obsolete files from cleanup

Change-Id: I6aa51b4ac2b392f786aeb12647be5073e6d02df5
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/14485
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed