gpio-pxa: gpio0 and gpio1 support on dt

pxa_gpio_probe() has some issues supporting the gpio0 and gpio1
interrupts under device-tree - it never actually sets up the chain
handler to get interrupts on edge detect for GPIO0 and GPIO1.

Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>