irqchip/loongson-liointc: Add IRQCHIP_SKIP_SET_WAKE flag

LIOINTC doesn't require specific logic to work with wakeup IRQs,
and no irq_set_wake callback is needed. To allow registered IRQs
from LIOINTC to be used as a wakeup-source, and ensure irq_set_irq_wake()
works well, the flag IRQCHIP_SKIP_SET_WAKE should be added.

Reviewed-by: Huacai Chen <[e-mail]>
Signed-off-by: Yinbo Zhu <[e-mail]>
Signed-off-by: Jianmin Lv <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/irqchip/irq-loongson-liointc.c

···
 	ct->chip.irq_mask = irq_gc_mask_disable_reg;
 	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
 	ct->chip.irq_set_type = liointc_set_type;
+	ct->chip.flags = IRQCHIP_SKIP_SET_WAKE;
 
 	gc->mask_cache = 0;
 	priv->gc = gc;