irqchip/crossbar: Restore set_wake functionality

The TI crossbar irqchip doesn't provides any facility to configure the
wakeup sources, but the conversion to hierarchical irqdomains set the
irq_set_wake callback to irq_chip_set_wake_parent. The parent chip
(OMAP wakeupgen) has no irq_set_wake function either so the call will
fail with -ENOSYS. As a result the irq_set_wake() call in the resume
path will trigger an 'Unbalanced wake disable' warning.

Before the conversion the GIC irqchip was the top level irqchip and
correctly flagged with IRQCHIP_SKIP_SET_WAKE.

Restore the correct behaviour by removing the irq_set_type callback
from the crossbar irqchip and set the IRQCHIP_SKIP_SET_WAKE flag which
lets the irq_set_irq_wake() call from the driver succeed.

[ tglx: Massaged changelog ]

Fixes: 783d31863f ('irqchip: crossbar: Convert dra7 crossbar...')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.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: <tony@atomide.com>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-7-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/irqchip/irq-crossbar.c

@@ -68,9 +68,9 @@ static struct irq_chip crossbar_chip = {
 	.irq_mask		= irq_chip_mask_parent,
 	.irq_unmask		= irq_chip_unmask_parent,
 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
-	.irq_set_wake		= irq_chip_set_wake_parent,
 	.irq_set_type		= irq_chip_set_type_parent,
-	.flags			= IRQCHIP_MASK_ON_SUSPEND,
+	.flags			= IRQCHIP_MASK_ON_SUSPEND |
+				  IRQCHIP_SKIP_SET_WAKE,
 #ifdef CONFIG_SMP
 	.irq_set_affinity	= irq_chip_set_affinity_parent,
 #endif