thermal: core: Drop the .set_trip_hyst() thermal zone operation

None of the users of the thermal core provides a .set_trip_hyst()
thermal zone operation, so drop that callback from struct
thermal_zone_device_ops and update trip_point_hyst_store()
accordingly.

No functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/thermal/thermal_sysfs.c

@@ -174,18 +174,11 @@ trip_point_hyst_store(struct device *dev, struct device_attribute *attr,
 	trip = &tz->trips[trip_id];
 
 	if (hyst != trip->hysteresis) {
-		if (tz->ops.set_trip_hyst) {
-			ret = tz->ops.set_trip_hyst(tz, trip_id, hyst);
-			if (ret)
-				goto unlock;
-		}
-
 		trip->hysteresis = hyst;
 
 		thermal_zone_trip_updated(tz, trip);
 	}
 
-unlock:
 	mutex_unlock(&tz->lock);
 
 	return ret ? ret : count;

include/linux/thermal.h

@@ -91,7 +91,6 @@ struct thermal_zone_device_ops {
 	int (*change_mode) (struct thermal_zone_device *,
 		enum thermal_device_mode);
 	int (*set_trip_temp) (struct thermal_zone_device *, int, int);
-	int (*set_trip_hyst) (struct thermal_zone_device *, int, int);
 	int (*get_crit_temp) (struct thermal_zone_device *, int *);
 	int (*set_emul_temp) (struct thermal_zone_device *, int);
 	int (*get_trend) (struct thermal_zone_device *,