Change in coreboot[master]: mb/google/volteer: adjust the size for RO/RW mcache

[Julius Werner (Code Review)]

Attention is currently required from: Furquan Shaikh, Nick Vaccaro, Zhuohao Lee.
Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/53908 )

Change subject: mb/google/volteer: adjust the size for RO/RW mcache
......................................................................

Patch Set 2:

(1 comment)

Patchset:

PS2:
> Agree with you about the RW_PERCENTAGE. […]

In that case, I would just set the size for those specific chipsets to 8K and the default for everything else to 16K. I think defaults should always be set so they'll do the right thing for new stuff that will be added in the future, and I assume the available CAR size should only get bigger on future chipsets. Might as well make sure less people will run into trouble with this in the future.