net/mlx5: Add cap bits for flow table destination in FDB table

If set, the FDB table supports the forward action with a
destination list that includes a flow table.

Signed-off-by: Chris Mi <chrism@mellanox.com>
Reviewed-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>