Change in flashrom[staging]: helpers: Add swap_byte() and swap_bytes()

[Urja Rannikko (Code Review)]

Urja Rannikko has posted comments on this change. ( https://review.coreboot.org/19993 )

Change subject: helpers: Add swap_byte() and swap_bytes()
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Patch Set 1:

Looks relatively good, but I looked at the ch341a use of swap_byte(), and your use of swap_bytes in the j-link patch, so...

I think we could instead use a swapping_memcpy() (someone, suggest a better name?) that copies the bytes from buffer to buffer while swapping them and adapt both to use that.