net/mlx5: Simplify IPsec flow steering init/cleanup functions

Remove multiple function wrappers to make sure that IPsec FS initialization
and cleanup functions present in one place to help with code readability.

Reviewed-by: Raed Salem <raeds@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>