Change in coreboot[master]: google/grunt: Override BayHub EMMC driving strength

[Kevin Chiu (Code Review)]

Kevin Chiu has uploaded a new patch set (#2). ( https://review.coreboot.org/27816 )

Change subject: google/grunt: Override BayHub EMMC driving strength
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google/grunt: Override BayHub EMMC driving strength

Careena EVT SanDisk EMMC sku has high fail rate of 0x5B reboot failure.
It'll need to increases 1.8V EMMC CLK/CMD,Data driving strength for this issue.

CLK[6:4]
CMD,DATA[3:1]

original: 0x6B
enhanced: 0x7F

BUG=b:111964336
BRANCH=master
TEST=emerge-grunt coreboot
Change-Id: I3db38ff12c566c258895c6643008a0472ca528bb
Signed-off-by: Kevin Chiu 
---
M src/drivers/generic/bayhub/bh720.c
A src/drivers/generic/bayhub/bh720.h
M src/mainboard/google/kahlee/variants/baseboard/mainboard.c
3 files changed, 77 insertions(+), 22 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/16/27816/2