power_supply: Add of_node_put to fix refcount

of_parse_phandle increments the refcount for a dt node before returning
it. Add of_node_put where needed to properly decrement the refcount when
we are done using a given node.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>