[M] Change in coreboot[main]: Add MTCL function to ACPI SSDT tables

[David Ruth (Code Review)]

Attention is currently required from: Arthur Heymans, Cliff Huang, Lance Zhao, Nico Huber, Paul Menzel, Subrata Banik, Subrata Banik, Tim Wawrzynczak.

David Ruth has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/80170?usp=email )

Change subject: Add MTCL function to ACPI SSDT tables
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Patch Set 14:

(1 comment)

File src/include/mtcl.h:

https://review.coreboot.org/c/coreboot/+/80170/comment/f0fa82fd_a3bbe939 :
PS8, Line 21: __packed
> I think I'll leave it as packed only because it's used to do a cast from an array. […]

Added a comment about the struct and how it's meant to be used, as well as why it's explicitly packed. Please reopen if you disagree.