net/mlx5: Simplify IPsec capabilities logic

Reduce number of hard-coded IPsec capabilities by making sure
that mlx5_ipsec_device_caps() sets only supported bits.

As part of this change, remove _ACCEL_ notations from the capabilities
names as they represent IPsec-capable device, so it is aligned with
MLX5_CAP_IPSEC() macro. And prepare the code to IPsec full offload mode.

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