mac80211: unconditionally start new netdev queues with iTXQ support

When internal mac80211 TXQs aren't supported, netdev queues must
always started out started even when driver queues are stopped
while the interface is added. This is necessary because with the
internal TXQ support netdev queues are never stopped and packet
scheduling/dropping is done in mac80211.

Cc: stable@vger.kernel.org # 4.9+
Fixes: 80a83cfc ("mac80211: skip netdev queue control with software queuing")
Reported-and-tested-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>