Fix tolerance issue in CL Winograd InputTransform FP16

Change-Id: I2874e1f3ff3f0b02edf465073a4a2de5171f0504
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5036
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Giorgio Arena <giorgio.arena@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/CL/Winograd.cpp b/tests/validation/CL/Winograd.cpp
index 750799a..115f937 100644
--- a/tests/validation/CL/Winograd.cpp
+++ b/tests/validation/CL/Winograd.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020 Arm Limited.
+ * Copyright (c) 2018-2021 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -55,7 +55,7 @@
 // *INDENT-OFF*
 // clang-format off
 constexpr AbsoluteTolerance<float> tolerance_f32(0.002f);
-const AbsoluteTolerance<half> tolerance_f16(half(0.5f));
+const AbsoluteTolerance<half> tolerance_f16(half(1.f));
 constexpr AbsoluteTolerance<float> tolerance_convolution_layer_f32(0.1f);
 const AbsoluteTolerance<half> tolerance_convolution_layer_f16(half(0.4f));
 RelativeTolerance<half_float::half> rel_tolerance_f16(half(0.2)); /**< Tolerance value for comparing reference's output against implementation's output for FP16 data types */