IVGCVSW-4439: Adding Elu support to Activation

 * Added CpuRef implementation
 * Added Unit Tests
 * Added Quantizer Test
 * Enabled Tests for Neon and CL backends on fp32 only
 * Added to Serializer

Signed-off-by: David Monahan <david.monahan@arm.com>
Change-Id: Ic23e1797dbc9352b40678c389d7fe2b836b582ea
diff --git a/src/backends/backendsCommon/test/layerTests/ActivationTestImpl.hpp b/src/backends/backendsCommon/test/layerTests/ActivationTestImpl.hpp
index 2251ceb..2830118 100644
--- a/src/backends/backendsCommon/test/layerTests/ActivationTestImpl.hpp
+++ b/src/backends/backendsCommon/test/layerTests/ActivationTestImpl.hpp
@@ -149,6 +149,22 @@
         const armnn::IBackendInternal::IMemoryManagerSharedPtr& memoryManager);
 
 //
+// Elu
+//
+
+LayerTestResult<float, 4> EluTest(
+        armnn::IWorkloadFactory& workloadFactory,
+        const armnn::IBackendInternal::IMemoryManagerSharedPtr& memoryManager);
+
+LayerTestResult<uint8_t, 4> EluUint8Test(
+        armnn::IWorkloadFactory& workloadFactory,
+        const armnn::IBackendInternal::IMemoryManagerSharedPtr& memoryManager);
+
+LayerTestResult<int16_t, 4> EluInt16Test(
+        armnn::IWorkloadFactory& workloadFactory,
+        const armnn::IBackendInternal::IMemoryManagerSharedPtr& memoryManager);
+
+//
 // Abs
 //