IVGCVSW-6620 Update the async api to use ExecutionData

* ExecutionData holds a void* which can be assigned to data required
  for execution in a backend. WorkingMemDescriptors are used in the Ref
  backend which hold TensorHandles for inputs and outputs.
* Updated ExecuteAsync functions to take ExecutionData.
* Added CreateExecutionData and UpdateExectutionData to IBackendInternal.
* Streamlined experimental IWorkingMemHandle API by removing map related
  function and unused m_workingMemDescriptorMap from WorkingMemHandle.

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: I54b0aab12872011743a141eb42dae200227769af
diff --git a/src/backends/reference/workloads/RefDepthwiseConvolution2dWorkload.cpp b/src/backends/reference/workloads/RefDepthwiseConvolution2dWorkload.cpp
index fd11ad1..c0677c9 100644
--- a/src/backends/reference/workloads/RefDepthwiseConvolution2dWorkload.cpp
+++ b/src/backends/reference/workloads/RefDepthwiseConvolution2dWorkload.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright © 2017 Arm Ltd. All rights reserved.
+// Copyright © 2022 Arm Ltd and Contributors. All rights reserved.
 // SPDX-License-Identifier: MIT
 //
 
@@ -41,9 +41,10 @@
     Execute(m_Data.m_Inputs, m_Data.m_Outputs);
 }
 
-void RefDepthwiseConvolution2dWorkload::ExecuteAsync(WorkingMemDescriptor &workingMemDescriptor)
+void RefDepthwiseConvolution2dWorkload::ExecuteAsync(ExecutionData& executionData)
 {
-    Execute(workingMemDescriptor.m_Inputs, workingMemDescriptor.m_Outputs);
+    WorkingMemDescriptor* workingMemDescriptor = static_cast<WorkingMemDescriptor*>(executionData.m_Data);
+    Execute(workingMemDescriptor->m_Inputs, workingMemDescriptor->m_Outputs);
 }
 
 void RefDepthwiseConvolution2dWorkload::Execute(std::vector<ITensorHandle*> inputs,