mfd: arizona: Propagate irq_wake through to parent IRQ

If one of the internal Arizona IRQs is set as a wake source this needs
to be propogated back to the actual IRQ line that the Arizona device is
attached to.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/arizona-irq.c

@@ -152,10 +152,18 @@ static void arizona_irq_disable(struct irq_data *data)
 {
 }
 
+static int arizona_irq_set_wake(struct irq_data *data, unsigned int on)
+{
+	struct arizona *arizona = irq_data_get_irq_chip_data(data);
+
+	return irq_set_irq_wake(arizona->irq, on);
+}
+
 static struct irq_chip arizona_irq_chip = {
 	.name			= "arizona",
 	.irq_disable		= arizona_irq_disable,
 	.irq_enable		= arizona_irq_enable,
+	.irq_set_wake		= arizona_irq_set_wake,
 };
 
 static int arizona_irq_map(struct irq_domain *h, unsigned int virq,