net/mlx5e: Only support tx/rx pause setting for port owner

Only support changing tx/rx pause frame setting if the net device
is the vport group manager.

Fixes: 3c2d18ef ("net/mlx5e: Support ethtool get/set_pauseparam")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -1338,6 +1338,9 @@ int mlx5e_ethtool_set_pauseparam(struct mlx5e_priv *priv,
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int err;
 
+	if (!MLX5_CAP_GEN(mdev, vport_group_manager))
+		return -EOPNOTSUPP;
+
 	if (pauseparam->autoneg)
 		return -EINVAL;