gpio: rockchip: fix OF node leak in probe()

Driver code is leaking OF node reference from of_get_parent() in
probe().

Fixes: 936ee267 ("gpio/rockchip: add driver for rockchip gpio")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://lore.kernel.org/r/20240826150832.65657-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>