mt76: use udelay instead of usleep_range in mt76x2_mac_stop

usleep_range can cause excessive latency on channel change if waiting
for the MAC to stop fails. It will be forced to stop by the code
following that loop anyway.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mediatek/mt76/mt76x2_init.c

@@ -376,7 +376,7 @@ void mt76x2_mac_stop(struct mt76x2_dev *dev, bool force)
 		if ((mt76_rr(dev, MT_MAC_STATUS) &
 		     (MT_MAC_STATUS_RX | MT_MAC_STATUS_TX)) ||
 		    mt76_rr(dev, MT_BBP(IBI, 12))) {
-			usleep_range(10, 20);
+			udelay(1);
 			continue;
 		}