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

[Jianjun Wang (Code Review)]

Attention is currently required from: Hung-Te Lin, Rex-BC Chen, Paul Menzel, Angel Pons, Yu-Ping Wu.
Jianjun Wang 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 2:

(2 comments)

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

https://review.coreboot.org/c/coreboot/+/62933/comment/acad30a6_e66ea564 
PS1, Line 56: write64
> We should also add read/write API for this in pcie_common.h. For example, […]

Done

https://review.coreboot.org/c/coreboot/+/62933/comment/1c170327_ccd8c2ee 
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()

Done