thermal: of-thermal: allow setting trip_temp on hardware

In current of-thermal, the .set_trip_temp only support to
set trip_temp for SW. But some sensors support to set
trip_temp on hardware, so that can trigger interrupt,
shutdown or any other events.
This patch adds .set_trip_temp() callback in
thermal_zone_of_device_ops{}, so that the sensor device can
use it to set trip_temp on hardware.

Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>