[M] Change in flashrom[main]: erasure_layout: Add an option to sacrifice unchanged blocks for speed

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Aarya, Bill XIE.

Anastasia Klimchuk has posted comments on this change by Bill XIE. ( https://review.coreboot.org/c/flashrom/+/84721?usp=email )

Change subject: erasure_layout: Add an option to sacrifice unchanged blocks for speed
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Patch Set 8:

(1 comment)

Patchset:

PS8: 
I rebased and merged the conflict in flash.h (because another patch was submitted earlier today).

Also ran the test scenario from CB:84614 
Default case, without providing sacrifice ration option, erases in many small blocks.
With `--sacrifice-ratio=50` added to the last command, erase is happening once, for the whole chip.
So, it's working as expected.