Add support for triggering spectral scan upon a channel reset/change.

This is intended to support reporting FFT results during active channel
scans, for users who would like to fiddle around with writing applications
that do both FFT visualisation _and_ AP scanning.

* add a new ioctl to enable/trigger spectral scan at channel change/reset;
* set do_spectral consistently if it's enabled, so a channel set/reset
  will carry forth the correct PHY error configuration so frames
  are actually received;
* for NICs that don't do spectral scan, don't bother checking the
  spectral scan state on channel change/reset.

Tested:

* AR9280 - STA and scanning;
* AR5416 - STA, ensured that the SS code doesn't panic

0 files changed, 0 insertions, 0 deletions