devlink: send objects notifications during devlink reload

Currently, the notifications are only sent for params. People who
introduced other objects forgot to add the reload notifications here.

To make sure all notifications happen according to existing comment,
benefit from existence of devlink_notify_register/unregister() helpers
and use them in reload code.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>