gpiolib: clear irq handler and data in one go

gpiolib: clear irq handler and data in one go

Replace the two separate calls for clearing the irqchip's chained handler
and its data with a single irq_set_chained_handler_and_data() call.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>