mac80211: set NETIF_F_LLTX when using intermediate tx queues

When using iTXQ, tx sequence number allocation and statistics are run at
dequeue time. Because of that, it is safe to enable NETIF_F_LLTX, which
allows tx handlers to run on multiple CPUs in parallel.
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/mac80211/iface.c

@@ -1225,6 +1225,7 @@ static void ieee80211_if_setup(struct net_device *dev)
 static void ieee80211_if_setup_no_queue(struct net_device *dev)
 {
 	ieee80211_if_setup(dev);
+	dev->features |= NETIF_F_LLTX;
 	dev->priv_flags |= IFF_NO_QUEUE;
 }