irqchip/renesas-irqc: Propagate wake-up settings to parent

The renesas-irqc interrupt controller is cascaded to the GIC, but its
driver doesn't propagate wake-up settings to the parent interrupt
controller.

Since commit aec89ef7 ("irqchip/gic: Enable SKIP_SET_WAKE and
MASK_ON_SUSPEND"), the GIC driver masks interrupts during suspend, and
wake-up through gpio-keys now fails on r8a73a4/ape6evm.

Fix this by propagating wake-up settings to the parent interrupt
controller. There's no need to handle irq_set_irq_wake() failures, as
the renesas-irqc interrupt controller is always cascaded to a GIC, and
the GIC driver always sets SKIP_SET_WAKE since the aforementioned
commit.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/1441731636-17610-3-git-send-email-geert%2Brenesas@glider.beSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-renesas-irqc.c

@@ -121,6 +121,9 @@ static int irqc_irq_set_type(struct irq_data *d, unsigned int type)
 static int irqc_irq_set_wake(struct irq_data *d, unsigned int on)
 {
 	struct irqc_priv *p = irq_data_get_irq_chip_data(d);
+	int hw_irq = irqd_to_hwirq(d);
+
+	irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
 
 	if (!p->clk)
 		return 0;