x86/cpu: Increase max CPU count to 8192

The MAXSMP option is intended to enable silly large numbers of
CPUs for testing purposes.  The current value of 4096 isn't very
silly any longer as there are actual SGI machines that approach
6096 CPUs when taking HT into account.

Increase the value to a nice round 8192 to account for this and
allow for short term future increases.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: prarit@redhat.com
Cc: Russ Anderson <rja@sgi.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20131105143816.GK9944@hansolo.jdub.homelinux.org


[ Tweaked it so that MAXSMP simply sets the maximum of the normal range. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>