Change in coreboot[master]: ec/google: Add support for ARTG method

[Varshit B Pandya (Code Review)]

Attention is currently required from: Poornima Tom, Tim Wawrzynczak, Paul Menzel, Rizwan Qureshi, Sumeet R Pawnikar, Eric Lai.
Varshit B Pandya has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/63949 )

Change subject: ec/google: Add support for ARTG method
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Patch Set 6:

(4 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/63949/comment/d3ff34e7_412d52d8 
PS5, Line 15: https://chromium-review.googlesource.com/c/
            : chromiumos/platform/ec/+/3545780
> `https://crrev.com/c/3545780%60 […]

Done

File src/ec/google/chromeec/acpi/emem.asl:

https://review.coreboot.org/c/coreboot/+/63949/comment/935b00ac_a2ed46b4 
PS2, Line 52: ARTG, 16,	// Adapter Rating
> At present, we are testing DTT features on brya using legacy EC cahnges, as brya doesn't still suppo […]

Done

File src/ec/google/chromeec/ec_dptf_helpers.c:

https://review.coreboot.org/c/coreboot/+/63949/comment/2e522400_54666aae 
PS5, Line 155: /* Local0 *= 0x32 */
> why does it need to be multiplied by 50?

Done

https://review.coreboot.org/c/coreboot/+/63949/comment/582430d7_7e07fece 
PS5, Line 165: acpigen_pop_len
> `acpigen_write_method_end()`

Done