arm64: defconfig: Enable NUMA and NUMA_BALANCING

Since much more arm64 SoCs with numa nodes, it's better to enable
NUMA and NUMA_BALANCING to improve the performance on test.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>