[S] Change in flashrom[main]: dummyflasher: Enable higher frequency emulation, add docs and tests

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Sergii Dmytruk.

Anastasia Klimchuk has posted comments on this change by Anastasia Klimchuk. ( https://review.coreboot.org/c/flashrom/+/84423?usp=email )

Change subject: dummyflasher: Enable higher frequency emulation, add docs and tests
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Patch Set 3:

(5 comments)

Patchset:

PS3: 
Thanks for suggestions for documentation, that's so useful.
I also added tests to cover freq initialisation code.

File doc/classic_cli_manpage.rst:

https://review.coreboot.org/c/flashrom/+/84423/comment/7e1d67f3_6ba3ebdc?usp... :
PS2, Line 619: **Frequency**
> I'd document that the range is [1Hz, 8000Mhz] and there is no delay by default.

Done

https://review.coreboot.org/c/flashrom/+/84423/comment/2f589e96_22e6980e?usp... :
PS2, Line 620: emulated
> nit: […]

Done

https://review.coreboot.org/c/flashrom/+/84423/comment/6533d600_90cf7cc6?usp... :
PS2, Line 624: 	The delay is calculated based on the assumption that we only work with bytes and transfer at 1 bit/Hz::
>

Done

File dummyflasher.c:

https://review.coreboot.org/c/flashrom/+/84423/comment/76a14afb_857ab910?usp... :
PS2, Line 1169: 		if (freq == 0) {
> A similar check could be added for an upper bound. […]

Done