Implement the discovery -v command line interface

Call the previously implemented get_rdcd_version and rdc_get_smiversion

Change-Id: If76037d462fa9328c3af8c85423ee4547882e36e
Signed-off-by: Chen Gong <curry.gong@amd.com>

rdci/include/RdciDiscoverySubSystem.h

@@ -38,6 +38,8 @@ class RdciDiscoverySubSystem : public RdciSubSystem {
   void show_help() const;
   bool is_list_;
   void show_attributes();
+  bool show_version_;
+  void show_version();
 };
 
 }  // namespace rdc