[M] Change in coreboot[master]: mb/google/myst: Add new mainboard

[Felix Held (Code Review)]

Attention is currently required from: Raul Rangel, Martin L Roth, Jon Murphy, Eric Lai, Martin Roth, Tim Van Patten, Karthik Ramasubramanian, Mark Hasemeyer.

Felix Held has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74093 )

Change subject: mb/google/myst: Add new mainboard
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Patch Set 7:

(1 comment)

File src/mainboard/google/myst/dsdt.asl:

https://review.coreboot.org/c/coreboot/+/74093/comment/c7720e06_316227bc 
PS2, Line 16: 	Name(LIDS, 0)
> I didn't see who use this in AMD SoC code. And this is in chrome EC LID device code. https://source. […]

The LIDS object is used by the EC and not by the SoC. the code you linked is the bit inside the chrome EC's EMEM; the LIDS object is separate from that. IIRC the \LIDS = LIDS statement copies the data from one into the other; both have different scopes. the LIDS object doesn't need to be in GNVS and is also not used by the SoC itself, so i removed it from the AMD SoC's GNVS and added it to the Chromebook's DSDT file.
The better solution would be to move the LIDS object to the EC code too, but reworking that is very much out of scope for me, since it's now only in Intel SoC and different EC code.
right now there's nothing to do here; this is a possible future improvement though