[PATCH] disable per cpu intr in /proc/stat

Don't compute and display the per-irq sums on ia64 either, too much
overhead for mostly useless figures.

Cc: Olaf Hering <olh@suse.de>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>