ACPI: Add LoongArch support for ACPI_PROCESSOR/ACPI_NUMA

We are preparing to add new Loongson (based on LoongArch, not MIPS)
support. LoongArch use ACPI other than DT as its boot protocol, so
add its support for ACPI_PROCESSOR/ACPI_NUMA.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>