Change in flashrom[master]: ich_descriptor.c: Simplify get_density lookups by deduplicate sw

[Anastasia Klimchuk (Code Review)]

Attention is currently required from: Nico Huber, Subrata Banik, Thomas Heijligen, Edward O'Callaghan.
Anastasia Klimchuk has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/63321 )

Change subject: ich_descriptor.c: Simplify get_density lookups by deduplicate sw
......................................................................

Patch Set 3: Code-Review+1

(1 comment)

File ich_descriptors.c:

https://review.coreboot.org/c/flashrom/+/63321/comment/a306f1d7_50e4ef34 
PS3, Line 167: static int get_density(enum ich_chipset cs, const struct ich_descriptors *desc, uint8_t idx, uint8_t *size_enc, uint8_t *size_max)
> Can you provide information about the meaning of the return values?

The idea is great, thanks for the patch!

I agree with Thomas, it would be good to have clear description of what are possible return values, and what each of them mean. Especially because `get_density()` is now called in two different contexts, and each of the contexts is treating return values differently.
For example, one of the callers treats -2 and -1 differently, the other caller doesn't care.