Move CPU/GPU files from Core/Runtime to the respective backend folders

Legacy structure contained two libraries core/runtime with two backends
in each.
We reduce the core/runtime libraries to a single library thus merging
the backend files

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I69545765fe7a730368105cdbd067d3135ec7a174
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6155
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/CL/Helper.h b/tests/CL/Helper.h
index e3e64c9..dd5e864 100644
--- a/tests/CL/Helper.h
+++ b/tests/CL/Helper.h
@@ -29,8 +29,8 @@
 #include "arm_compute/runtime/CL/functions/CLFill.h"
 #include "arm_compute/runtime/IFunction.h"
 #include "src/core/CL/kernels/CLFillBorderKernel.h"
-#include "src/runtime/gpu/cl/IClOperator.h"
-#include "src/runtime/gpu/cl/operators/ClFill.h"
+#include "src/gpu/cl/IClOperator.h"
+#include "src/gpu/cl/operators/ClFill.h"
 
 #include "src/core/CL/ICLKernel.h"
 #include "support/Cast.h"