[coreboot-gerrit] Change in coreboot[master]: documentation: Add documentation on setting up mainboard GPIOs

[Justin TerAvest (Code Review)]

Justin TerAvest has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/37802 )

Change subject: documentation: Add documentation on setting up mainboard GPIOs
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Patch Set 3: Code-Review+2