mfd: Add itps65910 wakeup support

Implementing irq_set_wake() so that device should able
to wakeup the system through different interrupt provided
by this device like gpios, onkey, rtc etc.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/tps65910-irq.c

@@ -145,12 +145,23 @@ static void tps65910_irq_disable(struct irq_data *data)
 	tps65910->irq_mask |= ( 1 << irq_to_tps65910_irq(tps65910, data->irq));
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int tps65910_irq_set_wake(struct irq_data *data, unsigned int enable)
+{
+	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
+	return irq_set_irq_wake(tps65910->chip_irq, enable);
+}
+#else
+#define tps65910_irq_set_wake NULL
+#endif
+
 static struct irq_chip tps65910_irq_chip = {
 	.name = "tps65910",
 	.irq_bus_lock = tps65910_irq_lock,
 	.irq_bus_sync_unlock = tps65910_irq_sync_unlock,
 	.irq_disable = tps65910_irq_disable,
 	.irq_enable = tps65910_irq_enable,
+	.irq_set_wake = tps65910_irq_set_wake,
 };
 
 int tps65910_irq_init(struct tps65910 *tps65910, int irq,