Change in coreboot[master]: soc/mediatek: Add timestamp to measure PERST# time

[Rex-BC Chen (Code Review)]

Attention is currently required from: Hung-Te Lin, Angel Pons, Yu-Ping Wu, Jianjun Wang.
Rex-BC Chen has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62933 )

Change subject: soc/mediatek: Add timestamp to measure PERST# time
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Patch Set 1:

(2 comments)

Patchset:

PS1: 
this patch should be put after CB:62934, or it will build fail.

File src/mainboard/google/cherry/bootblock.c:

https://review.coreboot.org/c/coreboot/+/62933/comment/745a5813_63bb6bfc 
PS1, Line 53: if (CONFIG(COLLECT_TIMESTAMPS) &&
            : 		    REGION_SIZE(pcie_timestamp) > 0) {
            : 			uint64_t timestamp = timestamp_get();
            : 			write64(_pcie_timestamp, timestamp);
            : 		}
I think we should put them inside mtk_pcie_pre_init()