soc: rockchip: power-domain: fix err handle while probing

If we fail to probe the driver, we should not directly break
from the for_each_available_child_of_node since it calls of_node_get
while iterating. This patch add of_node_put to fix the unbalanced
call pair.

Fixes: 7c696693 ("soc: rockchip: power-domain: Add power domain driver")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>