Change in coreboot[master]: soc/mediatek: add new driver 'msdc' for eMMC

[Wenbin Mei (Code Review)]

Attention is currently required from: Angel Pons, Wenbin Mei, Yu-Ping Wu.
Hello Hung-Te Lin, Xi Chen, build bot (Jenkins), Patrick Georgi, Martin Roth, Angel Pons, Yu-Ping Wu, Yidi Lin,

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

https://review.coreboot.org/c/coreboot/+/51966

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

Change subject: soc/mediatek: add new driver 'msdc' for eMMC
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soc/mediatek: add new driver 'msdc' for eMMC

Add MTK host mmc driver support.
MTK host controller support eMMC5.1 spec.

BUG=b:177389446
TEST=emerge-asurada coreboot
BRANCH=asurada

Signed-off-by: Wenbin Mei 
Change-Id: I54a7749ed167c00cd631a76af7c67c654c7bc725
---
M src/commonlib/include/commonlib/sd_mmc_ctrlr.h
A src/soc/mediatek/common/include/soc/msdc.h
A src/soc/mediatek/common/msdc.c
3 files changed, 668 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/66/51966/7