[XS] Change in coreboot[main]: UPSTREAM: soc/mediatek/common: Fix eMMC clock

[Yidi Lin (Code Review)]

Attention is currently required from: Hung-Te Lin, Kiwi Liu, Mengqi Zhang, Yu-Ping Wu.

Yidi Lin has posted comments on this change by Kiwi Liu. ( https://review.coreboot.org/c/coreboot/+/84298?usp=email )

Change subject: UPSTREAM: soc/mediatek/common: Fix eMMC clock
......................................................................

Patch Set 3:

(4 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/84298/comment/3620ad95_e8ff6d1e?usp... :
PS3, Line 7: UPSTREAM: 
remove

https://review.coreboot.org/c/coreboot/+/84298/comment/dc8e658a_be65de96?usp... :
PS3, Line 9: Mediatek SOC start operating at eMMC clock around 2 MHz
           : right after power-on.
           : In JEDEC spec, this period is 400 kHz or less.
```
MediaTek SoC operates eMMC clock around 2 MHz right after power-on. In JEDEC spec, the operating clock should be 400 kHz or less.
```
Please wrap the text at 72 characters.

https://review.coreboot.org/c/coreboot/+/84298/comment/e9a3dedc_48b28991?usp... :
PS3, Line 14: emerge-corsola coreboot
I don't think this is a proper test method.

https://review.coreboot.org/c/coreboot/+/84298/comment/822335c4_4cac224f?usp... :
PS3, Line 19: Tested-by: Konishi Yoshi 
            : Reviewed-by: Konishi Yoshi 
remove