net: mvpp2: make sure we use single queue mode on PPv2.1

The PPv2 driver defines 2 "queue_modes" :
 - QDIST_SINGLE_MODE, where each port share one rx queue vector
   between all CPUs
 - QDIST_MULTI_MODE, where each port has one rx queue vector per CPU.

Multi queue mode isn't available on PPv2.1, make sure we fallback to
single mode when running on this revision.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c

@@ -5014,6 +5014,12 @@ static int mvpp2_probe(struct platform_device *pdev)
 			(unsigned long)of_device_get_match_data(&pdev->dev);
 	}
 
+	/* multi queue mode isn't supported on PPV2.1, fallback to single
+	 * mode
+	 */
+	if (priv->hw_version == MVPP21)
+		queue_mode = MVPP2_QDIST_SINGLE_MODE;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(base))