Loading the NF CCA values may take longer than expected to occur.
If it does, don't then try reprogramming the NF "cap" values (ie
what values are the "maximum" value the NF can be) - instead,
just leave the current CCA value as the NF cap.

This was inspired by some similar work from ath9k. It isn't
a 100% complete solution (as there may be some reason where a
high NF CCA/cap is written, causing the baseband to stop thinking it
is able to transmit, leading to stuck beacon and interface reset)
which I'll investigate and look at fixing in a later commit.

Obtained from: Linux