Since PXA_GPIO_TO_IRQ() & MMP_GPIO_TO_IRQ() macro are depended on
arch code, move them from gpio driver to platform driver instead.
Signed-off-by: NHaojian Zhuang <haojian.zhuang@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>