[L] Change in coreboot[main]: acpi: Add PPTT support

[David Milosevic (Code Review)]

Attention is currently required from: Arthur Heymans, Cliff Huang, Lance Zhao, Martin L Roth, Maximilian Brune, Nico Huber, Patrick Rudolph, Tim Wawrzynczak.

David Milosevic has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/78071?usp=email )

Change subject: acpi: Add PPTT support
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Patch Set 19:

(3 comments)

File src/acpi/acpi_pptt.c:

https://review.coreboot.org/c/coreboot/+/78071/comment/c4ea6f7a_c24e0d43 :
PS17, Line 12: typedef
> I was also about to mention the pattern in acpigen code. However, […]

Removing typedefs would elongate the signatures even more, so I would like to keep them, if possible. Also, right now, one can easily distinguish between structures that are passed in by user (struct without typedefs) and structures solely used by the ACPI subsystem (structs with typedefs).

https://review.coreboot.org/c/coreboot/+/78071/comment/8de644c5_974db633 :
PS17, Line 23:  = 0x0
> Doesnt hurt to make it explicit, though?

Done

https://review.coreboot.org/c/coreboot/+/78071/comment/8c312332_4ecc4547 :
PS17, Line 74: u32 *n_caches
> I see no need for null-termination as reference_for_cache() already […]

I dont like the idea of iterating over the array only to insert a new element. I will try to pack it all in a struct, although not my favorite approach either.