ARM64 numa implementation is generic enough that RISC-V can reuse that
implementation with very minor cosmetic changes. This will help both
ARM64 and RISC-V in terms of maintanace and feature improvement

Move the numa implementation code to common directory so that both ISAs
can reuse this. This doesn't introduce any function changes for ARM64.
Signed-off-by: NAtish Patra <atish.patra@wdc.com>
Acked-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NPalmer Dabbelt <palmerdabbelt@google.com>