Change in coreboot[master]: WIP: soc/mediatek/mt8192: adjust i2c tLOW, tSU,STO

[Jg Daolongzhu (Code Review)]

Attention is currently required from: Jg Daolongzhu, 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/+/51024

to look at the new patch set (#7).

Change subject: WIP: soc/mediatek/mt8192: adjust i2c tLOW, tSU,STO
......................................................................

WIP: soc/mediatek/mt8192: adjust i2c tLOW, tSU,STO

The i2c actiming with the default reg setting cannot meet spec,
so we need to set some regs.
1. adjust the ratio of SCL high and low level, to adjust tLOW.
2. modify ext_conf reg to adjust tSU,STO.

BUG=b:179000159
TEST=Test on asurada (MT8192), boot pass,
timing pass.

Signed-off-by: jg_daolongzhu 
Change-Id: Ifbe97edbc38972af5b782fb93342ee0616127dd8
---
M src/soc/mediatek/mt8192/i2c.c
1 file changed, 28 insertions(+), 3 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/24/51024/7