IVGCVSW-3813 Add Unary Elementwise Operation 'NEG' support to the android-nn-driver

* Implemented ClNegWorkload
* Implemented NeonNegWorkload
* Enabled 'NEG' operator on CL and Neon as well as Ref
* Implemented unit tests for 'NEG' operator

Signed-off-by: Sadik Armagan <sadik.armagan@arm.com>
Change-Id: I3d7a892692716636cae6bdf8ddd238e3d1ea064f
diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index 7d3600c..551a7b5 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -774,13 +774,14 @@
 {
     IgnoreUnused(descriptor);
 
-    std::array<DataType, 5> supportedTypes =
+    std::array<DataType, 6> supportedTypes =
     {
         DataType::BFloat16,
         DataType::Float32,
         DataType::Float16,
         DataType::QAsymmU8,
-        DataType::QSymmS16
+        DataType::QSymmS16,
+        DataType::Signed32
     };
 
     bool supported = true;