Add suspend/resume support for HTVEC irqchip, which is needed for
upcoming suspend/hibernation.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020073527.541845-2-chenhuacai@loongson.cn