COMPMID-516 Change the CL CNN validation functions to use relative
tolerance error

Change-Id: Iec6347af26ea2a83c911f5fe10e6048e8a2a47ba
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/85381
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Moritz Pflanzer <moritz.pflanzer@arm.com>
diff --git a/tests/validation/CL/NormalizationLayer.cpp b/tests/validation/CL/NormalizationLayer.cpp
index 4d14649..35f7f72 100644
--- a/tests/validation/CL/NormalizationLayer.cpp
+++ b/tests/validation/CL/NormalizationLayer.cpp
@@ -45,8 +45,9 @@
 namespace
 {
 /** Tolerance for float operations */
-constexpr AbsoluteTolerance<float> tolerance_f16(0.01f);
-constexpr AbsoluteTolerance<float> tolerance_f32(0.00001f);
+RelativeTolerance<half_float::half> tolerance_f16(half_float::half(0.2));
+RelativeTolerance<float>            tolerance_f32(0.05f);
+
 /** Tolerance for fixed point operations */
 constexpr AbsoluteTolerance<int8_t>  tolerance_qs8(2);
 constexpr AbsoluteTolerance<int16_t> tolerance_qs16(2);