COMPMID-2764: Add support for QASYMM8_SIGNED in NEConvolutionLayer.

Change-Id: I8fbbd2e399f48968337a60147098d04f27c2d1c0
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/2402
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/reference/ActivationLayer.cpp b/tests/validation/reference/ActivationLayer.cpp
index 6cdba09..7a699c5 100644
--- a/tests/validation/reference/ActivationLayer.cpp
+++ b/tests/validation/reference/ActivationLayer.cpp
@@ -66,6 +66,17 @@
 }
 
 template <>
+SimpleTensor<int8_t> activation_layer<int8_t>(const SimpleTensor<int8_t> &src, ActivationLayerInfo info, const QuantizationInfo &oq_info)
+{
+    const QuantizationInfo dst_qinfo = oq_info.empty() ? src.quantization_info() : oq_info;
+
+    SimpleTensor<float>  src_tmp = convert_from_asymmetric(src);
+    SimpleTensor<float>  dst_tmp = activation_layer<float>(src_tmp, info);
+    SimpleTensor<int8_t> dst     = convert_to_asymmetric<int8_t>(dst_tmp, dst_qinfo);
+    return dst;
+}
+
+template <>
 SimpleTensor<int16_t> activation_layer<int16_t>(const SimpleTensor<int16_t> &src, ActivationLayerInfo info, const QuantizationInfo &oq_info)
 {
     const QuantizationInfo dst_qinfo = oq_info.empty() ? src.quantization_info() : oq_info;