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>

drivers/irqchip/irq-renesas-intc-irqpin.c

@@ -454,10 +454,8 @@ static int intc_irqpin_probe(struct platform_device *pdev)
 	irq_chip->name = name;
 	irq_chip->irq_mask = disable_fn;
 	irq_chip->irq_unmask = enable_fn;
-	irq_chip->irq_enable = enable_fn;
-	irq_chip->irq_disable = disable_fn;
 	irq_chip->irq_set_type = intc_irqpin_irq_set_type;
-	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE;
+	irq_chip->flags	= IRQCHIP_SKIP_SET_WAKE | IRQCHIP_MASK_ON_SUSPEND;
 
 	p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 					      p->number_of_irqs,