[M] Change in flashrom[master]: writeprotect,ichspi,spi25: handle register access constraints

[Nikolai Artemiev (Code Review)]

Attention is currently required from: Subrata Banik, Edward O'Callaghan, Angel Pons.

Nikolai Artemiev has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/69129 )

Change subject: writeprotect,ichspi,spi25: handle register access constraints
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Patch Set 6:

(1 comment)

This change is ready for review.

File spi25_statusreg.c:

https://review.coreboot.org/c/flashrom/+/69129/comment/0342556a_3b83e048 
PS5, Line 110: (struct flashctx *)
> Isn't this casting away `const` from the data pointed by `flash`?

Indeed, this was a hack to get it working in the cros fork that I forgot about.

I've created a patch to make probe_opcode take a const pointer so we can drop the case here.