platform/surface: aggregator: Add missing fwnode_handle_put()

In fwnode_for_each_child_node(), we should add
fwnode_handle_put() when break out of the iteration
fwnode_for_each_child_node() as it will automatically
increase and decrease the refcounter.

Fixes: fc622b3d

 ("platform/surface: Set up Surface Aggregator device registry")
Signed-off-by: Liang He <windhl@126.com>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20230322033057.1855741-1-windhl@126.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>