nl80211: use_monitor and non-mac80211 drivers

[Johannes Berg]

> > The monitor interface is something pretty much historic, we should
> > perhaps consider removing support for it - it hasn't been used for
> > about 5 years, since kernel 3.3 I believe.
> 
> Oh, that's something new for me. I still use (...) interface add mon0
> type monitor and I can see many howtos saying to do that.
> 
> What's the new way of getting whole packets with radiotap header?

Oh, no, that use case certainly is perfectly valid and there is nothing
to replace it.

I was referring only to the "cooked monitor" mode that hostapd uses to
get "all frames the kernel didn't handle".

Sorry I didn't make that clear.

johannes