net: microchip: sparx5: Improve the IP frame key match for IPv6 frames

This ensures that it will be possible for a VCAP rule to distinguish IPv6
frames from non-IP frames, as the IS0 keyset usually selected for the IPv6
traffic class in (7TUPLE) does not offer a key that specifies IPv6
directly: only non-IPv4.

The IP_SNAP key ensures that we select (at least) IP frames.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/sparx5/sparx5_tc_flower.c

@@ -266,6 +266,14 @@ sparx5_tc_flower_handler_basic_usage(struct sparx5_tc_flower_parse_usage *st)
 						    VCAP_BIT_0);
 			if (err)
 				goto out;
+			if (st->admin->vtype == VCAP_TYPE_IS0) {
+				err = vcap_rule_add_key_bit(st->vrule,
+							    VCAP_KF_IP_SNAP_IS,
+							    VCAP_BIT_1);
+				if (err)
+					goto out;
+			}
+
 		}
 	}