drm/amd/display/dmub/src/dmub_srv_stat: Convert function header to kernel-doc

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/amd/amdgpu/../display/dmub/src/dmub_srv_stat.c:38: warning: Cannot understand  *****************************************************************************

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jun Lei <Jun.Lei@amd.com>
Cc: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dmub/src/dmub_srv_stat.c

@@ -35,20 +35,13 @@
  */
 
 /**
- *****************************************************************************
- *  Function: dmub_srv_stat_get_notification
+ * dmub_srv_stat_get_notification - Retrieves a dmub outbox notification, set up dmub notification
+ *                                  structure with message information. Also a pending bit if queue
+ *                                  is having more notifications
+ *  @dmub: dmub srv structure
+ *  @notify: dmub notification structure to be filled up
  *
- *  @brief
- *		Retrieves a dmub outbox notification, set up dmub notification
- *		structure with message information. Also a pending bit if queue
- *		is having more notifications
- *
- *  @param [in] dmub: dmub srv structure
- *  @param [out] pnotify: dmub notification structure to be filled up
- *
- *  @return
- *     dmub_status
- *****************************************************************************
+ *  Returns: dmub_status
  */
 enum dmub_status dmub_srv_stat_get_notification(struct dmub_srv *dmub,
 						struct dmub_notification *notify)