[M] Change in coreboot[master]: cpu/intel/socket_*: Clean up Kconfig files

[Elyes Haouas (Code Review)]

Attention is currently required from: Stefan Ott, Nico Huber, Angel Pons, Arthur Heymans, Kyösti Mälkki, Alexander Couzens.

Elyes Haouas has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/69447 )

Change subject: cpu/intel/socket_*: Clean up Kconfig files
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Patch Set 3:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/69447/comment/14424e28_5849d034 
PS3, Line 10: Move MAX_CPUS to mainboards.
> > Set the max CPUs in socket Kconfig doesn't make sense!
>
> Why? The sockets you changed in this patch are well-defined:
> BGA956 is for low-power soldered-down Core 2 CPUs, which are paired with a GS45 northbridge (low-power variant of GM45). There are no quad-core CPUs in this package, so MAX_CPUS=2
> FCBGA559 is Pineview, but the CPU model is shared with Diamondville. These CPUs are dual-core with HyperThreading, so MAX_CPUS=4
> Socket P supports Core 2 Duo and (sometimes) Core 2 Quad CPUs, so MAX_CPUS=4
>
> For sockets like LGA775, the northbridges specify MAX_CPUS. Ironically enough, MAX_CPUS=4 for both of them.
> > Each socket can support only one CPU , however, a mainboard can have more than 1 socket (when the northbridge support it).
>
> Mainboards with more than 1 socket? None of the platforms affected by this change support more than 1 socket. It's also that can be addressed with a MAX_SOCKET Kconfig.

So the right place for MAX_CPUS should be at cpu/intel/model_*, isn't it?