The sx150x gpio driver used a loop to set liner irq map for gpio pins.
Now we use the irq domain to rebuild this irq mappig and make sure the
codes are still compatible to old users.

this patch also adds IRQF_ONESHOT flag to fix the IRQ flooding issues.
Signed-off-by: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
[Make Kconfig select GPIOLIB_IRQCHIP]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>