RDMA/mlx5: Implement MACsec gid addition and deletion

Handle MACsec IP ambiguity issue, since mlx5 hw can't support
programming both the MACsec and the physical gid when they have the same
IP address, because it wouldn't know to whom to steer the traffic.
Hence in such case we delete the physical gid from the hw gid table,
which would then cause all traffic sent over it to fail, and we'll only
be able to send traffic over the MACsec gid.

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Raed Salem <raeds@nvidia.com>
Reviewed-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>