net/mlx5e: Generalize IPsec work structs

IPsec logic has two work structs which are submitted to same workqueue.
As a preparation to addition of new work which needs to be submitted
too, let's generalize struct mlx5e_ipsec_work.

Link: https://lore.kernel.org/r/285a1550242363de181bab3a07a69296f66ad9a8.1680162300.git.leonro@nvidia.com


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