irqchip/ls-extirq: add IRQCHIP_SKIP_SET_WAKE to the irqchip flags

The ls-extirq driver doesn't implement the irq_set_wake()
callback, while being wake-up capable. This results in
ugly behaviours across suspend/resume cycles.

Advertise this by adding IRQCHIP_SKIP_SET_WAKE to
the irqchip flags

Fixes: b16a1caf ("irqchip/ls-extirq: Add LS1043A, LS1088A external interrupt support")
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210129095034.33821-1-biwen.li@oss.nxp.com