Add 64 bit loong_arch architecture by defining ACPI_MACHINE_WIDTH to 64.
Useful for acpica tools and incorporating ACPICA into the Firmware Test
Suite.
Link: https://github.com/acpica/acpica/commit/d809b69c Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>