net/mlx5e: Remove dependency in IPsec initialization flows
Currently, IPsec feature is disabled because mlx5e_build_nic_netdev
is required to be called after mlx5e_ipsec_init. This requirement is
invalid as mlx5e_build_nic_netdev and mlx5e_ipsec_init initialize
independent resources.
Remove ipsec pointer check in mlx5e_build_nic_netdev so that the
two functions can be called at any order.