ARM: OMAP: wakeupgen: Restore the irq_set_type() mechanism

ARM: OMAP: wakeupgen: Restore the irq_set_type() mechanism

The conversion of the wakeupgen irqchip to hierarchical irq domains
failed to provide a mechanism to properly set the trigger type of an
interrupt.

The wakeupgen irq chip itself has no mechanism and therefor no
irq_set_type() callback. The code before the conversion relayed the
trigger configuration directly to the underlying GIC.

Restore the correct behaviour by setting the wakeupgen irq_set_type
callback to irq_chip_set_type_parent(). This propagates the
set_trigger() call to the underlying GIC irqchip.

[ tglx: Massaged changelog ]

Fixes: 7136d457f365 ('ARM: omap: convert wakeupgen to stacked domains')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-5-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>