[M] Change in coreboot[master]: mb/google/myst: Enable AP <-> GSC communication

[Jon Murphy (Code Review)]

Attention is currently required from: Raul Rangel, Jon Murphy, Karthik Ramasubramanian, Mark Hasemeyer.

Hello build bot (Jenkins), Raul Rangel, Tim Van Patten, Karthik Ramasubramanian, Mark Hasemeyer,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/74111

to look at the new patch set (#24).

Change subject: mb/google/myst: Enable AP <-> GSC communication
......................................................................

mb/google/myst: Enable AP <-> GSC communication

Configure GSC I2C and Interrupt GPIOs during the early initialization.
Add devicetree configuration for GSC device and enable the required
config items.

BUG=b:275959717
TEST=builds

Change-Id: I6e235356b252a7b68a42da128ffd3189a829f117
Signed-off-by: Jon Murphy 
---
M src/mainboard/google/myst/Kconfig
M src/mainboard/google/myst/bootblock.c
M src/mainboard/google/myst/mainboard.c
M src/mainboard/google/myst/variants/baseboard/devicetree.cb
M src/mainboard/google/myst/variants/baseboard/gpio.c
M src/mainboard/google/myst/variants/baseboard/include/baseboard/variants.h
6 files changed, 70 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/11/74111/24