pinctrl: msm: drop wake_irqs bitmap

Currently, the wake_irqs bitmap is used to track whether there are any
gpio's which are configured as wake irqs, and uses this to determine
whether or not to call enable_irq_wake()/disable_irq_wake() on the
summary interrupt.

However, the genirq core already handles this case, by maintaining a
'wake_count' per irq_desc, and only calling into the controlling
irq_chip when wake_count transitions 0 <-> 1.

Drop this bitmap, and unconditionally call irq_set_irq_wake() on the
summary interrupt.

Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Acked-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>