thermal: cpu_cooling: update kernel-doc comment for cpufreq_cooling_unregister

Update comments for this exported function.

Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Acked-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c
index 9a1d82e..b4161cf 100644
--- a/drivers/thermal/cpu_cooling.c
+++ b/drivers/thermal/cpu_cooling.c
@@ -485,6 +485,8 @@
 /**
  * cpufreq_cooling_unregister - function to remove cpufreq cooling device.
  * @cdev: thermal cooling device pointer.
+ *
+ * This interface function unregisters the "thermal-cpufreq-%x" cooling device.
  */
 void cpufreq_cooling_unregister(struct thermal_cooling_device *cdev)
 {