[S] Change in coreboot[main]: soc/mediatek/common: Update timer macro name

[Yidi Lin (Code Review)]

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

Yidi Lin has posted comments on this change by Vince Liu. ( https://review.coreboot.org/c/coreboot/+/85681?usp=email )

Change subject: soc/mediatek/common: Update timer macro name
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Patch Set 1: Code-Review+2

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/85681/comment/04125692_b10fc09d?usp... :
PS1, Line 7: Update timer macro name
Replace GPT_MHZ with TIMER_MHZ for readability

https://review.coreboot.org/c/coreboot/+/85681/comment/95f905c5_76e9138f?usp... :
PS1, Line 11: The new ICs(e.g. mt8196, mt8189) will no longer use GPT, and in order
            : to improve code readability, so replace GPT_MHZ of existing Soc's
            : with macro name TIMER_MHZ.
The new ICs(e.g. mt8196, mt8189) is no longer using GPT. In order to improve code readability, replace GPT_MHZ with TIMER_MHZ for existing SoCs.