gpio: pl061: support irqdomain

Drop the support of irq generic chip. Now support irqdomain instead.

Although set_wake() is defined in irq generic chip & it is not really
used in pl061 gpio driver. Drop it at the same time.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>