perf: Bump max number of cpus to 1024

SPARC based systems currently support up to 1024 cpus (e.g. T5-8).
Allow perf to work on those systems.

Signed-off-by: David Ahern <david.ahern@oracle.com>
Link: http://lkml.kernel.org/r/1427213438-127216-1-git-send-email-david.ahern@oracle.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>