mt76: unify set_tim

All mt76 drivers (now also USB drivers) require empty .set_tim
callback. Add it to common mt76 module and use on all drivers.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt76.h

@@ -734,6 +734,8 @@ int mt76_get_txpower(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 void mt76_csa_check(struct mt76_dev *dev);
 void mt76_csa_finish(struct mt76_dev *dev);
 
+int mt76_set_tim(struct ieee80211_hw *hw, struct ieee80211_sta *sta, bool set);
+
 /* internal */
 void mt76_tx_free(struct mt76_dev *dev);
 struct mt76_txwi_cache *mt76_get_txwi(struct mt76_dev *dev);