COMPMID-1008: Fix Doxygen issues

Change-Id: Ie73d8771f85d1f5b059f3a56f1bbd73c98e94a38
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/124723
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/runtime/NEON/functions/NECannyEdge.h b/arm_compute/runtime/NEON/functions/NECannyEdge.h
index b7e0ffb..17fefcc 100644
--- a/arm_compute/runtime/NEON/functions/NECannyEdge.h
+++ b/arm_compute/runtime/NEON/functions/NECannyEdge.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 ARM Limited.
+ * Copyright (c) 2017-2018 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -56,6 +56,8 @@
     /** Constructor
      *
      * Initialize Sobel kernel to nullptr.
+     *
+     * @param[in] memory_manager (Optional) Memory manager.
      */
     NECannyEdge(std::shared_ptr<IMemoryManager> memory_manager = nullptr);
     /** Prevent instances of this class from being copied (As this class contains pointers) */