Change in coreboot[master]: soc/mediatek: move i2c function to common folder

[Rex-BC Chen (Code Review)]

Attention is currently required from: Hung-Te Lin, Xi Chen, Yu-Ping Wu.
Rex-BC Chen has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59295 )

Change subject: soc/mediatek: move i2c function to common folder
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Patch Set 6:

(2 comments)

File src/soc/mediatek/common/i2c.c:

https://review.coreboot.org/c/coreboot/+/59295/comment/cf88b96a_6a675b24 
PS5, Line 35:  { /* do nothing */ }
> Could you take the chance to fix this as well?

Done

https://review.coreboot.org/c/coreboot/+/59295/comment/ed605311_cb167ee1 
PS5, Line 549: This function is only used from MT8195.
> No need to mention this in the common file.

Done