net/mlx5e: Move devlink port register and unregister calls

Register devlink ports upon NIC init. TX and RX health reporters handle
errors which may occur early on at driver initialization. And because
these reporters are to be moved to port context, they require devlink
ports to be already registered.

Signed-off-by: Vladyslav Tarasiuk <vladyslavt@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>