qcacld-3.0: Remove wma_stats_event_handler() prototype

Function wma_stats_event_handler() was removed by:
  qcacld-3.0: Remove legacy implementation of stats event handler
  Change-Id I9a892b5f7486a406654256fc2cc8177f2fafe790

However, the prototype was left behind, so remove it now.

Change-Id: I8eba9a888c9dbb592b802fa3fd2e1fd0a824296d
CRs-Fixed: 3434497

core/wma/inc/wma_internal.h

@@ -1104,9 +1104,6 @@ int wma_link_status_event_handler(void *handle, uint8_t *cmd_param_info,
  */
 int wma_rso_cmd_status_event_handler(uint8_t vdev_id, uint32_t notif);
 
-int wma_stats_event_handler(void *handle, uint8_t *cmd_param_info,
-			    uint32_t len);
-
 QDF_STATUS wma_send_link_speed(uint32_t link_speed);
 
 int wma_link_speed_event_handler(void *handle, uint8_t *cmd_param_info,