pinctrl: nxp: Fix resource leaks in for_each_child_of_node() loops

Ensure child node references are decremented properly in the error path.

Signed-off-by: Lu Hongfei <luhongfei@vivo.com>
Link: https://lore.kernel.org/r/20230606070201.14249-1-luhongfei@vivo.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>