NNXSW-3081 Move Filesystem.hpp and Threads.hpp to public include

!android-nn-driver:5966

Change-Id: Ice0b4d2872bb0e09bfc0763034a206c3a8f24af4
Signed-off-by: Rob Hughes <robert.hughes@arm.com>
diff --git a/src/backends/cl/ClWorkloadFactory.cpp b/src/backends/cl/ClWorkloadFactory.cpp
index 6ca8c1b..4568177 100644
--- a/src/backends/cl/ClWorkloadFactory.cpp
+++ b/src/backends/cl/ClWorkloadFactory.cpp
@@ -29,7 +29,7 @@
 #include <arm_compute/runtime/CL/CLBufferAllocator.h>
 #include <arm_compute/runtime/CL/CLScheduler.h>
 
-#include <Filesystem.hpp>
+#include <armnnUtils/Filesystem.hpp>
 #include <fstream>
 
 namespace armnn