net/mlx5: Create bypass and loopback flow steering namespaces for RDMA RX

Use different namespaces for bypass and switchdev loopback because they
have different priorities and default table miss action requirement:
1. bypass: with multiple priorities support, and
   MLX5_FLOW_TABLE_MISS_ACTION_DEF as the default table miss action;
2. switchdev loopback: with single priority support, and
   MLX5_FLOW_TABLE_MISS_ACTION_SWITCH_DOMAIN as the default table miss
   action.

Signed-off-by: Mark Zhang <markz@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>