Hibernation: Introduce exportable suspend ioctls header (rev. 2)

Move the definitions of hibernation ioctls to a separate header file in
include/linux, which can be exported to the user space.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>