Change in coreboot[master]: mb/google/guybrush/var/nipperkin: config eSPI alert as in-band

[Kevin Chiu (Code Review)]

Attention is currently required from: Furquan Shaikh, Martin Roth, Bhanu Prakash Maiya, Paul Menzel, Rob Barnes, Eric Peers, Karthik Ramasubramanian.
Kevin Chiu has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57976 )

Change subject: mb/google/guybrush/var/nipperkin: config eSPI alert as in-band
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Patch Set 2:

(1 comment)

File src/mainboard/google/guybrush/variants/nipperkin/overridetree.cb:

https://review.coreboot.org/c/coreboot/+/57976/comment/43654789_bcde4f33 
PS2, Line 131: register "common_config.espi_config.alert_pin" = "ESPI_ALERT_PIN_IN_BAND"
> We observed eSPI bus errors during S0ix resume when using in-band alerts b/197965075. […]

hi Rob,
can't access b/197965075, could you please loop ODM group in? thank you!