devlink: warn about existing entities during reload-reinit

During reload-reinit, all entities except for params, resources, regions
and health reporter should be removed and re-added. Add a warning to
be triggered in case the driver behaves differently.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>