Makefile: Update payload clean targets

Move payload clean targets into payloads/Makefile.inc
Add clean targets for coreinfo, nvramcui, Memtest86+

Change-Id: I70c13582311dfba3e309805053159f8a039cb109
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13940
Tested-by: build bot (Jenkins)
Reviewed-by: Ben Gardner <gardner.ben@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
3 files changed