COMPMID-3637: Move utility headers from arm_compute to src

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: If9d6fa8c900b68c4b6fd373f2fc1f9abb83ea917
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4145
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Sang-Hoon Park <sang-hoon.park@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/GLES_COMPUTE/IGCSimpleKernel.cpp b/src/core/GLES_COMPUTE/IGCSimpleKernel.cpp
index 6609f45..fb31ac8 100644
--- a/src/core/GLES_COMPUTE/IGCSimpleKernel.cpp
+++ b/src/core/GLES_COMPUTE/IGCSimpleKernel.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 Arm Limited.
+ * Copyright (c) 2017-2020 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -27,6 +27,7 @@
 #include "arm_compute/core/IAccessWindow.h"
 #include "arm_compute/core/Validate.h"
 #include "arm_compute/core/Window.h"
+#include "src/core/helpers/WindowHelpers.h"
 
 using namespace arm_compute;