The BCM2836 interrupt controller doesn't provide any facility to
configure the wakeup sources. That's the reason why the driver lacks
the irq_set_wake() callback for the interrupt chip.
Enable the flags IRQCHIP_SKIP_SET_WAKE and IRQCHIP_MASK_ON_SUSPEND so
the interrupt suspend logic can handle the chip correctly.
This was inspired by the patch series "irqchip/irq-bcm283x update
for BCM7211" by Florian Fainelli.
Link: https://lore.kernel.org/lkml/20191001224842.9382-1-f.fainelli@xxxxxxxxx/
Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>