libre mrc on haswell is quite buggy for now, but works in
a limited fashion
this patch re-adds the old configs, but as _mrc for example
t440p_12mb_mrc instead of t440p_12mb
and t440p_12mb (without _mrc) still uses the libre mrc code
courtesy of Angel Pons from the coreboot project
this uses the following patch set from gerrit, as yet
unmerged (in coreboot master) on this date:
https://review.coreboot.org/c/coreboot/+/64198/5
logic for downloading mrc blobs has been deleted from
lbmk, as this is now completely obsolete (for haswell
boards)
if other platforms are added later that need mrc.bin,
then logic will be re-added again for that