irqchip: renesas-intc-irqpin: Add suspend-to-RAM wake up support

irqchip: renesas-intc-irqpin: Add suspend-to-RAM wake up support

Set the ->irq_enable() and ->irq_disable() methods to NULL to enable
lazy disable of interrupts, and set IRQCHIP_MASK_ON_SUSPEND to tell the
core that only IRQs marked as wake-ups need to stay enabled during
suspend-to-RAM.

This makes wake-up by gpio-keys from suspend-to-RAM work on
r8a7740/Armadillo.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/1408546172-22484-1-git-send-email-geert+renesas@glider.be
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
(cherry picked from commit 1c36d42c4ffee9e38e122ed822dd0a545a3a86da)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>