Change in flashrom[master]: programmer: Introduce default shutdown function

[Angel Pons (Code Review)]

Attention is currently required from: Nico Huber, Edward O'Callaghan, Anastasia Klimchuk.
Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/54890 )

Change subject: programmer: Introduce default shutdown function
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Patch Set 5: Code-Review+2

(1 comment)

Patchset:

PS5:
> There are two reasons why I thought of default shutdown function. […]

Personally, I don't mind adding something that ends up being removed later, as long as it provides some benefit. I can see why this `default_shutdown()` function may end up being unnecessary in the future, but this commit would ease (even if only slightly) follow-up works as there would be less shutdown functions to adapt and/or remove.