Change in coreboot[master]: soc/mediatek: Add mtk_early_init for passing data across sessions

[Yu-Ping Wu (Code Review)]

Attention is currently required from: Hung-Te Lin, Rex-BC Chen, Paul Menzel, Angel Pons, Jianjun Wang.
Yu-Ping Wu has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/63019 )

Change subject: soc/mediatek: Add mtk_early_init for passing data across sessions
......................................................................

Patch Set 1:

(7 comments)

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

https://review.coreboot.org/c/coreboot/+/63019/comment/1cfa4734_c08cd354 
PS1, Line 11: assert
This could be _Static_assert.

https://review.coreboot.org/c/coreboot/+/63019/comment/eb4f9865_fc95c221 
PS1, Line 25: void mtk_pcie_save_timestamp(void)
> Will it better if we move these pcie function to common/pcie. […]

Absolutely. This function doesn't belong here.

https://review.coreboot.org/c/coreboot/+/63019/comment/c5bce85c_9b12ef98 
PS1, Line 27: timestamp
cur_time

https://review.coreboot.org/c/coreboot/+/63019/comment/98652661_b3ef3493 
PS1, Line 35: microseconds
We shouldn't access the field directly (see the comment in include/timer.h). The whole mono_time struct should be stored in the mtk_early_init region, and the elapsed time should be obtained by mono_time_diff_microseconds().

File src/soc/mediatek/common/include/soc/early_init.h:

https://review.coreboot.org/c/coreboot/+/63019/comment/6f56041a_4d89fba9 
PS1, Line 10: mtk_early_init
I'd prefer "early_init_data".

https://review.coreboot.org/c/coreboot/+/63019/comment/0360c98e_e5427606 
PS1, Line 10: mtk_early_init
I'd prefer "early_init_data".

https://review.coreboot.org/c/coreboot/+/63019/comment/fe7c1642_e004bab4 
PS1, Line 17: mtk_pcie_save_timestamp
> What about […]

This also works. Then we can keep these functions in this file.