net/mlx5: Fix irq affinity management

The cited patch deny the user of changing the affinity of mlx5 irqs,
which break backward compatibility.
Hence, allow the user to change the affinity of mlx5 irqs.

Fixes: bbac70c7

 ("net/mlx5: Use newer affinity descriptor")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>