[M] Change in flashrom[master]: opaque: make opaque programmers expose register read/write capability

[Nikolai Artemiev (Code Review)]

Attention is currently required from: Thomas Heijligen, Edward O'Callaghan, Sergii Dmytruk.

Nikolai Artemiev has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/66032 )

Change subject: opaque: make opaque programmers expose register read/write capability
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Patch Set 3:

(1 comment)

File ichspi.c:

https://review.coreboot.org/c/flashrom/+/66032/comment/d7b8cf43_906bceb6 
PS2, Line 1413: static bool ich_hwseq_can_read_register(const struct flashctx *flash, enum flash_reg reg)
              : {
              : 	return reg == STATUS1;
              : }
              : 
              : static bool ich_hwseq_can_write_register(const struct flashctx *flash, enum flash_reg reg)
              : {
              : 	return reg == STATUS1;
              : }
> Possibly the programmer fills a instance of `struct reg_bit_info` and the writeprotect implementatio […]

It might be better to use functions instead of structs, given the many-to-one relationship between devices and drivers. I.e. we could have multiple devices with different register access capabilities that use the same driver.

This doesn't apply to the ich hwseq master afaik, but it could if we need to use this abstraction for another programmer.