Quoting myself:

> This tends to increase the size of the three set_store_regs_fan_div
> functions, and I am considering refactoring them at some point. Later
> though.

Here is the promised refactoring. Tested on my AS99127F rev.1, seems to
work. As for the previous patch, there is a part that I cannot test with
the AS99127F, so additional testing is welcome.

I agree this makes the code slightly less readable, but this saves 60
lines of code (1754 bytes, around 3% of the driver total), and is
actually far less complex that I first feared.