Change in flashrom[master]: ichspi: Extract handling programmer param into a function

[Anastasia Klimchuk (Code Review)]

Attention is currently required from:  Felix Singer, Nico Huber, Edward O'Callaghan, Angel Pons, Nikolai Artemiev.
Anastasia Klimchuk has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/58736 )

Change subject: ichspi: Extract handling programmer param into a function
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Patch Set 3:

(2 comments)

File ichspi.c:

https://review.coreboot.org/c/flashrom/+/58736/comment/def3e7d0_1ced7ea7 
PS1, Line 1760: *arg
> Could be `*const arg`.

Done

File ichspi.c:

https://review.coreboot.org/c/flashrom/+/58736/comment/31cc0208_631b783b 
PS2, Line 1764: arg
> idea: explicitly handle the case of `!arg` (i.e. user did not specify `ich_spi_mode`) first? […]

Just checking: this idea can go in a separate commit, right?