Implement Set function for MAC address

Change-Id: I16992dda259246a66512792f06cbbb874e56a15d
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/vlan_interface.hpp b/vlan_interface.hpp
index d9ea078..3f273b7 100644
--- a/vlan_interface.hpp
+++ b/vlan_interface.hpp
@@ -63,6 +63,12 @@
                    and creates the vlan interface.*/
         void writeDeviceFile();
 
+        /** @brief copy the mac address from the parent interface.*/
+        void updateMacAddress()
+        {
+            MacAddressIntf::mACAddress(parentInterface.mACAddress());
+        }
+
     private:
 
         /** @brief VLAN Identifier. */