arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4

arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4

The current arm64 default config limits max NUMA nodes available on
system to 4 (NODES_SHIFT = 2). Today's arm64 systems can reach or
exceed 16 NUMA nodes. To accomodate current hardware and to fit
NODES_SHIFT within page flags on arm64, increase NODES_SHIFT to 4.

Signed-off-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20201020173409.1266576-1-vanshikonda@os.amperecomputing.com/
Link: https://lore.kernel.org/r/20201030173050.1182876-1-vanshikonda@os.amperecomputing.com
Signed-off-by: Will Deacon <will@kernel.org>