[S] Change in coreboot[master]: mb/google/myst: Add FW_CONFIG

[Jon Murphy (Code Review)]

Attention is currently required from: Raul Rangel, Eric Lai, Tim Van Patten, Karthik Ramasubramanian, Mark Hasemeyer.

Jon Murphy has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74102 )

Change subject: mb/google/myst: Add FW_CONFIG
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Patch Set 5:

(1 comment)

File src/mainboard/google/myst/variants/myst/overridetree.cb:

https://review.coreboot.org/c/coreboot/+/74102/comment/ac611a6d_56a858ba 
PS4, Line 20:
> Do we need EMMC and NVME too? Also SD card?

I don't believe so.  We only add fields for things that we need to know at boot and/or aren't queryable.

For reference, look at Skyrim: https://docs.google.com/spreadsheets/d/12TKNyhDUwTOVnmIehWQxVb0J7tj_sLUY6oNd...

And Myst: https://docs.google.com/spreadsheets/d/1CtfZr42hX4nnlswomMDDZfvGEmZycQxFFr4U...