When support suspend/resume for loongson-pch-pic, the syscore_ops
is registered twice in dual-bridges machines where there are two
pch-pic IRQ domains. Repeated registration of an same syscore_ops
broke syscore_ops_list, so the patch will corret it.

Fixes: 1ed008a2 ("irqchip/loongson-pch-pic: Add suspend/resume support")
Cc: stable@vger.kernel.org
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230407083453.6305-5-lvjianmin@loongson.cn