IVGCVSW-2604 Fix bug that made it impossible to execute inference tests on certain backends

* Read compute devices from the CL as strings and convert them into BackendId objects afterwards

Change-Id: Icded1c572778f5a213644e3052ff6dfe7022128b
Signed-off-by: Aron Virginas-Tar <Aron.Virginas-Tar@arm.com>
diff --git a/tests/InferenceTest.inl b/tests/InferenceTest.inl
index 4dde354..07a20d5 100644
--- a/tests/InferenceTest.inl
+++ b/tests/InferenceTest.inl
@@ -342,7 +342,7 @@
                     }
 
                     modelParams.m_IsModelBinary = isModelBinary;
-                    modelParams.m_ComputeDevice = modelOptions.m_ComputeDevice;
+                    modelParams.m_ComputeDevices = modelOptions.GetComputeDevicesAsBackendIds();
                     modelParams.m_VisualizePostOptimizationModel = modelOptions.m_VisualizePostOptimizationModel;
                     modelParams.m_EnableFp16TurboMode = modelOptions.m_EnableFp16TurboMode;