Move the implementation for writing conf to interface class

implementation of writing interface conf to the
ethernet interface class.

Change-Id: I279afff45a82ca92c4e50810664f7a7c69a66a61
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/ethernet_interface.hpp b/ethernet_interface.hpp
index 0ab849c..4617f56 100644
--- a/ethernet_interface.hpp
+++ b/ethernet_interface.hpp
@@ -113,12 +113,14 @@
          */
         void createVLAN(VlanId id);
 
+        /** @brief write the network conf file with the in-memory objects.
+         */
+        void writeConfigurationFile();
+
+
         using EthernetInterfaceIntf::dHCPEnabled;
         using EthernetInterfaceIntf::interfaceName;
 
-        /** @brief Network Configuration directory. */
-        fs::path confDir;
-
     protected:
 
         /** @brief get the info of the ethernet interface.
@@ -159,6 +161,9 @@
                                       uint8_t prefixLength,
                                       const std::string& gateway);
 
+        /** @brief write the dhcp section **/
+        void writeDHCPSection(std::fstream& stream);;
+
         /** @brief Persistent sdbusplus DBus bus connection. */
         sdbusplus::bus::bus& bus;