Add a getter for belonging subsystem in subsystem objects

BZ: 66692

Sometimes, subsystem object need to know their belonging subsystem.

Change-Id: Ia1b8c8c3756179a87b542fc0fe52f6f0097299b6
Signed-off-by: Guillaume Denneulin <guillaume.denneulin@intel.com>
Reviewed-on: http://android.intel.com:8080/87951
Reviewed-by: Soulard, Mathieu <mathieu.soulard@intel.com>
Reviewed-by: Centelles, Sylvain <sylvain.centelles@intel.com>
Tested-by: Dixon, CharlesX <charlesx.dixon@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
diff --git a/parameter/SubsystemObject.cpp b/parameter/SubsystemObject.cpp
index 15bba6c..d79789b 100644
--- a/parameter/SubsystemObject.cpp
+++ b/parameter/SubsystemObject.cpp
@@ -253,3 +253,9 @@
 {
     return _pInstanceConfigurableElement;
 }
+
+// Belonging Subsystem retrieval
+const CSubsystem* CSubsystemObject::getSubsystem() const
+{
+    return _pInstanceConfigurableElement->getBelongingSubsystem();
+}