net/mlx5: add fate actions to switch flow rules

net/mlx5: add fate actions to switch flow rules

This patch enables creation of rte_flow rules that direct matching traffic
to a different port (e.g. another VF representor) or drop it directly at
the switch level (PORT_ID and DROP actions).

Testpmd examples:

- Directing all traffic to port ID 0:

  flow create 1 ingress transfer pattern end actions port_id id 0 / end

- Dropping all traffic normally received by port ID 1:

  flow create 1 ingress transfer pattern end actions drop / end

Note the presence of the transfer attribute, which requests them to be
applied at the switch level. All traffic is matched due to empty pattern.

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
Acked-by: Yongseok Koh <yskoh@mellanox.com>