hw/loongarch/virt: Replace Loongson IPI with LoongArch IPI

hw/loongarch/virt: Replace Loongson IPI with LoongArch IPI

Loongarch IPI inherits from class LoongsonIPICommonClass, and it
only contains Loongarch 3A5000 virt machine specific interfaces,
rather than mix different machine implementations together.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
[PMD: Rebased]
Co-Developed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20240805180622.21001-14-philmd@linaro.org>