mac80211: Allow drivers to differentiate between ROC types

Some devices can handle remain on channel requests differently
based on the request type/priority. Add support to
differentiate between different ROC types, i.e., indicate that
the ROC is required for sending managment frames.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>