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

[Nico Huber (Code Review)]

Attention is currently required from: Stefan Ott, Arthur Heymans, Kyösti Mälkki, Alexander Couzens, Elyes Haouas.

Nico Huber 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)

Patchset:

PS3: 
For instruction set extensions like SSE, should we have a `default y`
in the sockets and a potential `default n` opt-out for the CPUs that
don't support it? That is, if we have sockets that support CPUs with
and without an extension.