gpio/rockchip: Convert to generic_handle_domain_irq()

Follow commit dbd1c54f ("gpio: Bulk conversion to
generic_handle_domain_irq()").

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>