Without an ->irq_set_wake() method in an irq_chip, calls to
enable_irq_wake() will fail.  This also causes these interrupts to not
be able to abort suspend (via check_wakeup_irqs() in late suspend.)

Currently, we don't implement ->irq_set_wake() for INTC interrupts
because they default to be wakeup enabled by setting the GRPSEL bits
in PM init.  Even though there is no ->irq_set_wake(), we want
enable_irq_wake() to succeed so these interrupts can abort suspend
when necessary.

To fix, set IRQCHIP_SKIP_SET_WAKE flag for all the INTC
interrupts which avoids trying to check irq_chip->irq_set_wake()
and failing when it doesn't exist.

Longer term, we need to implement ->irq_set_wake() for the INTC
which can manage the appropriate GRPSEL bits.
Signed-off-by: NeilBrown <neilb@suse.de>
[khilman@ti.com: rework changelog]
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>