cpu: change cpu_sys_devices from array to per_cpu variable

Change cpu_sys_devices from array to per_cpu variable in drivers/base/cpu.c.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>