net/mlx5: Add missing RDMA_RX capabilities

New flow table type RDMA_RX was added but the MLX5_CAP_FLOW_TABLE_TYPE
didn't handle this new flow table type.
This means that MLX5_CAP_FLOW_TABLE_TYPE returns an empty capability to
this flow table type.

Update both the macro and the maximum supported flow table type to
RDMA_RX.

Fixes: d83eb50e

 ("net/mlx5: Add support in RDMA RX steering")
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>