COMPMID-767 : Propagate hints to subgraph.

-Propagates hints to subgraph.
-Fixes dispatching of apropriate optimized DepthwiseConvolution kernel
for OpenCL backend. NEON backend is altered to default to the generic
case until COMPMID-769 is addressed.

Change-Id: I544f05cd99a9ac253f1b19aa4e4bb222b8fdd087
Reviewed-on: https://eu-gerrit-1.euhpc.arm.com/114781
Reviewed-by: Pablo Tello <pablo.tello@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Jenkins <bsgcomp@arm.com>
diff --git a/src/graph/SubGraph.cpp b/src/graph/SubGraph.cpp
index 977cd4a..f62b261 100644
--- a/src/graph/SubGraph.cpp
+++ b/src/graph/SubGraph.cpp
@@ -52,13 +52,13 @@
     }
 }
 
-std::unique_ptr<Graph> SubGraph::construct(TargetHint hint, std::unique_ptr<ITensorObject> input, std::unique_ptr<ITensorObject> output)
+std::unique_ptr<Graph> SubGraph::construct(const GraphContext &ctx, std::unique_ptr<ITensorObject> input, std::unique_ptr<ITensorObject> output)
 {
     auto graph = arm_compute::support::cpp14::make_unique<Graph>();
 
     // Set hint
     // TODO(geopin01): store hints of sub-graph
-    graph->hints().set_target_hint(hint);
+    graph->hints() = ctx.hints();
 
     // Configure input
     if(_input == nullptr)