[coreboot-gerrit] [XS] Change in coreboot[main]: soc/mediatek/common: Reduce eMMC clock frequency to 400kHz

[Yu-Ping Wu (Code Review)]

Attention is currently required from: Hung-Te Lin, Kiwi Liu, Mengqi Zhang, Paul Menzel, Yidi Lin.

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

Change subject: soc/mediatek/common: Reduce eMMC clock frequency to 400kHz
......................................................................

Patch Set 14:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/84298/comment/b30fa093_19012e22?usp... :
PS14, Line 13: he frequency
             : division value to 125
> and get the division value 125.

I don't think the origin code will give us the 125 value due to the division rounding error.

```
div = DIV_ROUND_UP(hclk, clock * 4)
    = DIV_ROUND_UP(50M / (400K * 4))
    = DIV_ROUND_UP(31.25)
    = 32
```

So the division value will be `div` * 4 = 128.