Fix wrong file inclusion in QLSTMLayerNormalization reference

Alter to include AsymmHelpers.h instead of AsymmHelpers.cpp

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: Ib8c470c232d70b011b3c307a4b2c8ab0ca782708
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4851
Reviewed-by: Giorgio Arena <giorgio.arena@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/reference/QLSTMLayerNormalization.cpp b/tests/validation/reference/QLSTMLayerNormalization.cpp
index 44d4f03..1a9bdc9 100644
--- a/tests/validation/reference/QLSTMLayerNormalization.cpp
+++ b/tests/validation/reference/QLSTMLayerNormalization.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Arm Limited.
+ * Copyright (c) 2020-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -27,7 +27,7 @@
 #include "MeanStdDevNormalizationLayer.h"
 #include "PixelWiseMultiplication.h"
 #include "arm_compute/core/utils/misc/Utility.h"
-#include "src/core/utils/quantization/AsymmHelpers.cpp"
+#include "arm_compute/core/utils/quantization/AsymmHelpers.h"
 
 namespace arm_compute
 {