COMPMID-2336: Account for padding in NEIm2ColKernel for NHWC.

Change-Id: I494c4acc95cb431b1718ae62c1504522a115ba10
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/1312
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Giuseppe Rossini <giuseppe.rossini@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/reference/Im2Col.h b/tests/validation/reference/Im2Col.h
index f519d0e..34b8476 100644
--- a/tests/validation/reference/Im2Col.h
+++ b/tests/validation/reference/Im2Col.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018 ARM Limited.
+ * Copyright (c) 2017-2019 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -35,7 +35,7 @@
 namespace reference
 {
 template <typename T>
-void im2col(const SimpleTensor<T> &src, SimpleTensor<T> &dst, const Size2D &kernel_dims, const PadStrideInfo &conv_info, bool has_bias, const unsigned int num_groups);
+void im2col(const SimpleTensor<T> &src, SimpleTensor<T> &dst, const Size2D &kernel_dims, const PadStrideInfo &conv_info, bool has_bias, unsigned int num_groups);
 } // namespace reference
 } // namespace validation
 } // namespace test