IVGCVSW-1988: Refactor backend-specific unit tests

Change-Id: I8eca81d2e0780390eaa837c186ffe1c7d41fdebe
diff --git a/src/backends/cl/CMakeLists.txt b/src/backends/cl/CMakeLists.txt
index a7ce893..04da6dd 100644
--- a/src/backends/cl/CMakeLists.txt
+++ b/src/backends/cl/CMakeLists.txt
@@ -15,7 +15,8 @@
 )
 
 if(ARMCOMPUTECL)
-    add_subdirectory(workloads test)
+    add_subdirectory(workloads)
+    add_subdirectory(test)
 endif()
 
 add_library(armnnClBackend STATIC ${armnnClBackend_sources})