[L] Change in coreboot[master]: mb/ibm: Add 4 SPR sockets server board IBM SBP1

[Jonathan Zhang (Code Review)]

Attention is currently required from: Patrick Rudolph, Johnny Lin, Paul Menzel, David Hendricks, Angel Pons, Shuo Liu, Nill Ge.

Jonathan Zhang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/73392 )

Change subject: mb/ibm: Add 4 SPR sockets server board IBM SBP1
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Patch Set 10:

(1 comment)

File src/mainboard/ibm/sbp1/Kconfig:

https://review.coreboot.org/c/coreboot/+/73392/comment/e7bcd283_592f586c 
PS9, Line 31: MAX_SOCKET_UPD
> The soc code has two Kconfigs. Please refer to the soc code authors for design related questions.

MAX_SOCKET_UPD matches with how the FSP was built. 
MAX_SOCKET is the maximum number of sockets supported by a mainboard.