Reorganize the code path of the rdci Discovery Subsystem

Prepare for adding 'detection version information' later

Change-Id: Ib2b5e70b2360b1c5ff87a537f41f34f23c7ed61f
Signed-off-by: Chen Gong <curry.gong@amd.com>

rdci/include/RdciDiscoverySubSystem.h

@@ -36,6 +36,8 @@ class RdciDiscoverySubSystem : public RdciSubSystem {
  private:
   bool show_help_;
   void show_help() const;
+  bool is_list_;
+  void show_attributes();
 };
 
 }  // namespace rdc