RDMA/mlx5: Add support for RDMA TX flow table

Enable user application to add rules for RDMA TX steering table.
Rules in this steering table will allow to steer transmitted RDMA
traffic.

Link: https://lore.kernel.org/r/20200324061425.1570190-3-leon@kernel.org
Signed-off-by: Michael Guralnik <michaelgur@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/flow.c

@@ -35,6 +35,9 @@ mlx5_ib_ft_type_to_namespace(enum mlx5_ib_uapi_flow_table_type table_type,
 	case MLX5_IB_UAPI_FLOW_TABLE_TYPE_RDMA_RX:
 		*namespace = MLX5_FLOW_NAMESPACE_RDMA_RX;
 		break;
+	case MLX5_IB_UAPI_FLOW_TABLE_TYPE_RDMA_TX:
+		*namespace = MLX5_FLOW_NAMESPACE_RDMA_TX;
+		break;
 	default:
 		return -EINVAL;
 	}