cfg80211: provide a function to report a match for NAN

Provide a function the driver can call to report a match.
This will send the event to the user space.
If the NAN instance is tied to the owner, the notifications will be
sent to the socket that started the NAN interface only.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>