hw/loongarch/virt: Enable extioi virt extension

This patch adds a new board attribute 'v-eiointc'.
A value of true enables the virt extended I/O interrupt controller.
VMs working in kvm mode have 'v-eiointc' enabled by default.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-Id: <20240528083855.1912757-4-gaosong@loongson.cn>
3 files changed