net/mlx5: Add stub for mlx5_eswitch_mode

Return MLX5_ESWITCH_NONE when CONFIG_MLX5_ESWITCH
is not selected.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

include/linux/mlx5/eswitch.h

@@ -61,7 +61,6 @@ void *mlx5_eswitch_get_proto_dev(struct mlx5_eswitch *esw,
 struct mlx5_eswitch_rep *mlx5_eswitch_vport_rep(struct mlx5_eswitch *esw,
 						u16 vport_num);
 void *mlx5_eswitch_uplink_get_proto_dev(struct mlx5_eswitch *esw, u8 rep_type);
-u8 mlx5_eswitch_mode(struct mlx5_eswitch *esw);
 struct mlx5_flow_handle *
 mlx5_eswitch_add_send_to_vport_rule(struct mlx5_eswitch *esw,
 				    u16 vport_num, u32 sqn);
@@ -75,7 +74,14 @@ mlx5_eswitch_get_encap_mode(const struct mlx5_core_dev *dev);
 bool mlx5_eswitch_vport_match_metadata_enabled(const struct mlx5_eswitch *esw);
 u32 mlx5_eswitch_get_vport_metadata_for_match(const struct mlx5_eswitch *esw,
 					      u16 vport_num);
+u8 mlx5_eswitch_mode(struct mlx5_eswitch *esw);
 #else  /* CONFIG_MLX5_ESWITCH */
+
+static inline u8 mlx5_eswitch_mode(struct mlx5_eswitch *esw)
+{
+	return MLX5_ESWITCH_NONE;
+}
+
 static inline enum devlink_eswitch_encap_mode
 mlx5_eswitch_get_encap_mode(const struct mlx5_core_dev *dev)
 {