Change in coreboot[master]: soc/mediatek/mt8192: use Mediatek mt8192 vendor code (CB:50294)

[Hung-Te Lin (Code Review)]

Attention is currently required from: Xi Chen, Cindy Ching, Martin Roth, Shaoming Chen, Paul Menzel, Duan huayang.
Hung-Te Lin has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/51125 )

Change subject: soc/mediatek/mt8192: use Mediatek mt8192 vendor code (CB:50294)
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Patch Set 24:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/51125/comment/327f215a_9a6b518e 
PS24, Line 7: soc/mediatek/mt8192: use Mediatek mt8192 vendor code (CB:50294)
            : 
            : Mediatek maintains the DRAM initialization code, the coding style
            : is different from coreboot, when CB:50294 is ready, soc/mediatek/mt8192
            : will not be used.
            : 
soc/mediatek/mt8192: initialize DRAM using vendor reference code

Mediatek has released the reference implementation for DRAM
initialization in vendor/mediatek/mt8192/dramc (CB:50294)
so we want to use it to replace the derived calibration code
in soc folder.