mfd: pm8921: Use IRQCHIP_SKIP_SET_WAKE

We don't need to implement a dummy irq_set_wake op if we just set
IRQCHIP_SKIP_SET_WAKE.

Suggested-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/pm8921-core.c b/drivers/mfd/pm8921-core.c
index 4d486e9..1153e8a 100644
--- a/drivers/mfd/pm8921-core.c
+++ b/drivers/mfd/pm8921-core.c
@@ -247,18 +247,12 @@
 	return pm8xxx_config_irq(chip, block, config);
 }
 
-static int pm8xxx_irq_set_wake(struct irq_data *d, unsigned int on)
-{
-	return 0;
-}
-
 static struct irq_chip pm8xxx_irq_chip = {
 	.name		= "pm8xxx",
 	.irq_mask_ack	= pm8xxx_irq_mask_ack,
 	.irq_unmask	= pm8xxx_irq_unmask,
 	.irq_set_type	= pm8xxx_irq_set_type,
-	.irq_set_wake	= pm8xxx_irq_set_wake,
-	.flags		= IRQCHIP_MASK_ON_SUSPEND,
+	.flags		= IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE,
 };
 
 /**