LoongArch: Add ACPI-based generic laptop driver

This add ACPI-based generic laptop driver for Loongson-3. Some of the
codes are derived from drivers/platform/x86/thinkpad_acpi.c.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>