gpio: dwapb: add missing fwnode_handle_put() in dwapb_gpio_get_pdata()

fwnode_handle_put() should be used when terminating
device_for_each_child_node() iteration with break or
return to prevent stale device node references from
being left behind.

Generated by Coccinelle.

Fixes: 4ba8cfa7 ("gpio: dwapb: convert device node to fwnode")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>