hw/loongarch/virt: Add reset support for kernel irqchip

hw/loongarch/virt: Add reset support for kernel irqchip

When system reboot, interrupt controller is restored to initial
state. However if interrupt controller extioi/ipi/pch_pic is
emulated in kernel, it should notify kvm to do so. Here suspend
and restore API is used for reset, set initial state in qemu user
space and restore API is used to notify kvm to reload register
state.

Reviewed-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20250606063033.2557365-11-maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>