[coreboot] Change-sets for AMD Stoney Ridge, unifying PI directories

[Paul Menzel]

Dear coreboot folks,

If you haven’t seen it yet, Marc uploaded change-sets for review adding
support for AMD Stoney Ridge (if I am not mistaken) [1][2], he and
Marshall worked on.

Are the different AMD PI using devices different enough, to have one
directory for each of them, or would it make sense to unify it?

Thanks,

Paul

[1] https://review.coreboot.org/17139
[2] https://review.coreboot.org/#/q/owner:%22Marc+Jones%22+status:open