Change in coreboot[master]: mb/google/corsola: set up open-drain ChromeOS pins

[Rex-BC Chen (Code Review)]

Attention is currently required from: Rex-BC Chen, Yu-Ping Wu.
Hello Hung-Te Lin, build bot (Jenkins), Yu-Ping Wu,

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

https://review.coreboot.org/c/coreboot/+/60002

to look at the new patch set (#3).

Change subject: mb/google/corsola: set up open-drain ChromeOS pins
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mb/google/corsola: set up open-drain ChromeOS pins

Set open-drain GPIOs for ChromeOS as input and high-z mode.
After apply this patch, we can measure these pins from 1.0V to correct
voltage (1.8V) to prevent wrong judgement of low/high.

Reference document:
MT8186_SoC_Pinmux_V1_1

BUG=b:209342636
TEST=measure pins voltage 1.8V on kingler board

Signed-off-by: Rex-BC Chen 
Change-Id: Ib55a773bb63404a1b952f7e7645eb7aba6638b00
---
M src/mainboard/google/corsola/bootblock.c
M src/mainboard/google/corsola/chromeos.c
M src/mainboard/google/corsola/gpio.h
3 files changed, 46 insertions(+), 19 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/02/60002/3