Change in coreboot[master]: soc/intel/xeon_sp: Add PCH lockdown

[Marc Jones (Code Review)]

Attention is currently required from: Furquan Shaikh, Martin Roth, Jonathan Zhang, Johnny Lin, Rocky Phagura, Stefan Reinauer, Angel Pons, Patrick Rudolph.
Marc Jones has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/49849 )

Change subject: soc/intel/xeon_sp: Add PCH lockdown
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Patch Set 4:

(3 comments)

Patchset:

PS4: 
Thanks, nice catch. I cleaned up the .h more. They had some cruft. I think we will add a me.c and print me info out in a future patch.

File src/soc/intel/xeon_sp/include/soc/itss.h:

https://review.coreboot.org/c/coreboot/+/49849/comment/30d47022_23936afa 
PS3, Line 3: SKL
> Hm?

Ack

File src/soc/intel/xeon_sp/include/soc/me.h:

https://review.coreboot.org/c/coreboot/+/49849/comment/1170be99_780edf6e 
PS3, Line 3: SKYLAKE
> hm?

Ack