mt76x2: add a polling delay in mt76x2_mac_stop routine

Add a usleep_range in mt76x2_mac_stop routine in order to add
a polling delay checking values of MT_MAC_STATUS and IBI_R12 registers

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

mt76x2_init.c

@@ -377,12 +377,12 @@ void mt76x2_mac_stop(struct mt76x2_dev *dev, bool force)
 
 	/* Wait for MAC to become idle */
 	for (i = 0; i < 300; i++) {
-		if (mt76_rr(dev, MT_MAC_STATUS) &
-		    (MT_MAC_STATUS_RX | MT_MAC_STATUS_TX))
-			continue;
-
-		if (mt76_rr(dev, MT_BBP(IBI, 12)))
+		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);
 			continue;
+		}
 
 		stopped = true;
 		break;