rename board configs, and add to sources file the
t530/w530 boards

in some situations, the files weren't being downloaded

MRC caches in a certain way, that Heads was able to work
around in their build system, for this board.

I've adapted the relevant config differences, from their project
as of heads revision 96440b928acb06de5b925ea12014c9c280b23165

The downside is that CBFS now has to be 8MB in size. The upside
is that the machine also boots much faster

See:

    https://github.com/osresearch/heads/pull/1282/commits/f0792117efa177ded19878f652c5a28e8cc62a71

    https://github.com/osresearch/heads/pull/1282#issuecomment-1400634600

I have not adapted their IFD changes, versus Libreboot, because theirs
simply has a different version string, and uses different read/write
permission bits for regions as defined in the IFD.

This affects:

    t440p_12mb_mrc

    w541_12mb_mrc

S3 suspend/resume still broken on these targets which use the libre
MRC init (replacement code by Angel Pons, recently merged in lbmk):

    t440p_12mb

    w541_12mb

With clever use of FMAP, the rest of the BIOS region might still be
used. However, for our purposes, 8MB CBFS will do just fine.

Heads's changes configure MRC so that caching is handled properly,
for when the machine returns from sleep. Setting CBFS to be any
higher will result in slower boot times, and broken S3 resume, due
to MRC cache misalignment (this is based on my understanding, reading
through the Heads project looking at their research on this).

At some point in the future, Angel's libre MRC code will probably
be finished, and merged, with more fine tuning possible to allow
bigger CBFS sizes.

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

i found that with libre mrc, usb was broken in grub

however, it worked nicely in seabios

for our purposes, doing seabios-only roms in text mode
is best for now

i'm going to re-add mrc.bin, but for t440p_12mb_mrc
and w541_12mb_mrc, as new config names. the regular
t440p_12mb and w541_12mb will continue to use libre
mrc, but the _mrc ones will use mrc.bin and retain the
grub payload in board.cfg

untested. removing.

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