Change in flashrom[master]: dummyflasher: Wire variable size feature via opaque infra

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Nico Huber, Angel Pons, Nikolai Artemiev.
Anastasia Klimchuk has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/64488 )

Change subject: dummyflasher: Wire variable size feature via opaque infra
......................................................................

Patch Set 4:

(2 comments)

Commit Message:

https://review.coreboot.org/c/flashrom/+/64488/comment/174f2492_e8a1e301 
PS2, Line 20: TEST
> A comment for myself: check with the users of "variable size" feature to make sure their stuff does  […]

It's all good! So I am closing this comment.

Patchset:

PS4: 
Testing done, and I rebased the patch on the latest. I also ran all the scenarios listed in commit message, and all of them work successfully.
So, ready! :)