If userspace requested control port frames to go over 80211, then do so.
The control packets are intercepted just prior to delivery of the packet
to the underlying network device.

Pre-authentication type frames (protocol: 0x88c7) are also forwarded
over nl80211.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>