List thermal_instance in thermal_cooling_device so that
cooling device can know the cooling state requirement
of all the thermal instances.
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Reviewed-by: NRafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: NEduardo Valentin <eduardo.valentin@ti.com>