[M] Change in flashrom[main]: ch347_spi: Add spi clock frequency selection

[ZhiYuanNJ (Code Review)]

Attention is currently required from: Anastasia Klimchuk, Nicholas Chin.

ZhiYuanNJ has posted comments on this change by ZhiYuanNJ. ( https://review.coreboot.org/c/flashrom/+/82776?usp=email )

Change subject: ch347_spi: Add spi clock frequency selection
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Patch Set 13:

(3 comments)

File ch347_spi.c:

https://review.coreboot.org/c/flashrom/+/82776/comment/14a59a3f_e41cd1cf?usp... :
PS7, Line 365: 30MHz
> I agree with this idea because the default value cannot be determined at the moment. […]

Done

File ch347_spi.c:

https://review.coreboot.org/c/flashrom/+/82776/comment/3830f60e_27cc7d96?usp... :
PS11, Line 291: speed_index = 1;
> Default speed_index also needs to be 2 (to index the entry 15M) […]

Done

File doc/classic_cli_manpage.rst:

https://review.coreboot.org/c/flashrom/+/82776/comment/c49cc22b_2929cce4?usp... :
PS11, Line 1025: The default SPI speed is 30MHz if no value is specified.
> Since we are returning back to 15M, you need to update here as well […]

Done