cfg80211: add wowlan net-detect support

Add a new WoWLAN API to enable net-detect as a wake up trigger.
Net-detect allows the device to scan in the background while the
host is asleep to wake up the host system when a matching network
is found.

Reuse the scheduled scan attributes to specify how the scan is
performed while suspended and the matches that will trigger a
wake event.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>