don't enable control method power button as wakeup device
when Fixed Power button is used.

http://bugzilla.kernel.org/show_bug.cgi?id=10503Tested-by: walken@zoy.org <walken@zoy.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>