COMPMID-2762: Add support for QASYMM8_SIGNED in CLReductionOperation and CLReduceMean

Change-Id: Ib6babd9ad80c57cf21c2f0ee2aab404221088595
Signed-off-by: Michalis Spyrou <michalis.spyrou@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2670
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
diff --git a/src/runtime/CL/functions/CLReductionOperation.cpp b/src/runtime/CL/functions/CLReductionOperation.cpp
index 2f9a386..e04982a 100644
--- a/src/runtime/CL/functions/CLReductionOperation.cpp
+++ b/src/runtime/CL/functions/CLReductionOperation.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 ARM Limited.
+ * Copyright (c) 2017-2020 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -271,6 +271,11 @@
                         pixelValue = PixelValue(255, input->info()->data_type(), input->info()->quantization_info());
                         break;
                     }
+                    case DataType::QASYMM8_SIGNED:
+                    {
+                        pixelValue = PixelValue(127, input->info()->data_type(), input->info()->quantization_info());
+                        break;
+                    }
                     default:
                     {
                         ARM_COMPUTE_ERROR("Unsupported DataType");
@@ -298,6 +303,11 @@
                         pixelValue = PixelValue(0, input->info()->data_type(), input->info()->quantization_info());
                         break;
                     }
+                    case DataType::QASYMM8_SIGNED:
+                    {
+                        pixelValue = PixelValue(-128, input->info()->data_type(), input->info()->quantization_info());
+                        break;
+                    }
                     default:
                     {
                         ARM_COMPUTE_ERROR("Unsupported DataType");