thermal: update kernel-doc for thermal_cooling_device_register

This patch updates the documentation for thermal_cooling_device_register
and removes the warnings generated by scripts/kernel-doc -v.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/thermal_core.c

@@ -1287,10 +1287,17 @@ static struct class thermal_class = {
 };
 
 /**
- * thermal_cooling_device_register - register a new thermal cooling device
+ * thermal_cooling_device_register() - register a new thermal cooling device
  * @type:	the thermal cooling device type.
  * @devdata:	device private data.
  * @ops:		standard thermal cooling devices callbacks.
+ *
+ * This interface function adds a new thermal cooling device (fan/processor/...)
+ * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
+ * to all the thermal zone devices registered at the same time.
+ *
+ * Return: a pointer to the created struct thermal_cooling_device or an
+ * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
  */
 struct thermal_cooling_device *
 thermal_cooling_device_register(char *type, void *devdata,