net/mlx5: fix flow creation on port start

net/mlx5: fix flow creation on port start

While the PMD avoids from creating hash RXQ with no hash fields and
array of queues after the port was already started, it lacks such
protection when re-creating the flows after the port restarts.

This may lead to inconsistent behavior for flows depending if they were
created before or after the port start.

Fixes: 8086cf08b2f0 ("net/mlx5: handle RSS hash configuration in RSS flow")
Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>