ACPICA: Change type of _TZ from ThermalZone to Device

The type of ThermalZone was confusing hosts as they process the
various ThermalZone objects. ACPICA BZ 876.

http://www.acpica.org/bugzilla/show_bug.cgi?id=876



Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>