[PATCH] ARM64: Dynamically allocate cpumasks and increase supported CPUs to 512

[Eric Mackay]

Whitespace issues aside, I have applied the patch on top of kernel 6.1.55 and tested on both a dual-socket Ampere Altra machine with < 256 CPUs, and a dual-socket AmpereOne machine with > 256 CPUs. Works as expected, with all CPUs visible and functional.

>   config NR_CPUS
>   	int "Maximum number of CPUs (2-4096)"
>   	range 2 4096
> - 	default "256"
> + 	default 512

Nit: the new default value should be in quotation marks, if we want to be pedantic

Tested-by: Eric Mackay <eric.mackay at oracle.com>