net/mlx5: Add back multicast stats for uplink representor

The multicast counter got removed from uplink representor due to the
cited patch.

Fixes: 47c97e6b ("net/mlx5e: Fix multicast counter not up-to-date in "ip -s"")
Signed-off-by: Huy Nguyen <huyn@nvidia.com>
Reviewed-by: Daniel Jurgens <danielj@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -3846,10 +3846,17 @@ mlx5e_get_stats(struct net_device *dev, struct rtnl_link_stats64 *stats)
 	}
 
 	if (mlx5e_is_uplink_rep(priv)) {
+		struct mlx5e_vport_stats *vstats = &priv->stats.vport;
+
 		stats->rx_packets = PPORT_802_3_GET(pstats, a_frames_received_ok);
 		stats->rx_bytes   = PPORT_802_3_GET(pstats, a_octets_received_ok);
 		stats->tx_packets = PPORT_802_3_GET(pstats, a_frames_transmitted_ok);
 		stats->tx_bytes   = PPORT_802_3_GET(pstats, a_octets_transmitted_ok);
+
+		/* vport multicast also counts packets that are dropped due to steering
+		 * or rx out of buffer
+		 */
+		stats->multicast = VPORT_COUNTER_GET(vstats, received_eth_multicast.packets);
 	} else {
 		mlx5e_fold_sw_stats64(priv, stats);
 	}