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/SConscript b/tests/SConscript
index 29ed739..7b05dcb 100644
--- a/tests/SConscript
+++ b/tests/SConscript
@@ -134,7 +134,7 @@
     filter_pattern = test_env['test_filter']
     files_benchmark += Glob('benchmark/NEON/*/' + filter_pattern)
     files_benchmark += Glob('benchmark/NEON/' + filter_pattern)
-    test_env.Append(CPPPATH = ["#/src/core/cpu/kernels/assembly/"])
+    test_env.Append(CPPPATH = ["#/src/cpu/kernels/assembly/"])
     if env['external_tests_dir']:
         files_benchmark += Glob(env['external_tests_dir'] + '/tests/benchmark/NEON/' + filter_pattern)