net/mlx5: Enable SD feature

Have an actual mlx5_sd instance in the core device, and fix the getter
accordingly. This allows SD stuff to flow, the feature becomes supported
only here.
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Gal Pressman <gal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/lib/mlx5.h

@@ -59,10 +59,11 @@ struct mlx5_sd;
 
 static inline struct mlx5_sd *mlx5_get_sd(struct mlx5_core_dev *dev)
 {
-	return NULL;
+	return dev->sd;
 }
 
 static inline void mlx5_set_sd(struct mlx5_core_dev *dev, struct mlx5_sd *sd)
 {
+	dev->sd = sd;
 }
 #endif

include/linux/mlx5/driver.h

@@ -822,6 +822,7 @@ struct mlx5_core_dev {
 	struct blocking_notifier_head macsec_nh;
 #endif
 	u64 num_ipsec_offloads;
+	struct mlx5_sd          *sd;
 };
 
 struct mlx5_db {