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

[Nicholas Chin (Code Review)]

Attention is currently required from: Anastasia Klimchuk, ZhiYuanNJ.

Nicholas Chin 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 10:

(1 comment)

File ch347_spi.c:

https://review.coreboot.org/c/flashrom/+/82776/comment/b6b6f8f8_292315d3?usp... :
PS7, Line 365: 30MHz
> If it is a Windows system, you can read it through the hardware ID of the device manager hardware de […]

Thanks. The region of mine is 1.40. I did some experimentation and found that if I set the SPI mode to 3 (polarity=1 and phase=1) in `ch347_spi_config()` I could get that Winbond chip working at 30 MHz and even 60 MHz. However, the Eon chip refused to work in anything but mode 0, and not at 30 MHz.