ONOS-6886 Move interface classes from incubator to core

Change-Id: Iaae4d98279e4b77fc3f0b5a63d547921f93aeb46
diff --git a/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
index 9abe49e..4475f54 100644
--- a/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
+++ b/apps/dhcprelay/src/main/java/org/onosproject/dhcprelay/Dhcp4HandlerImpl.java
@@ -38,8 +38,8 @@
 import org.onosproject.dhcprelay.api.DhcpHandler;
 import org.onosproject.dhcprelay.store.DhcpRecord;
 import org.onosproject.dhcprelay.store.DhcpRelayStore;
-import org.onosproject.incubator.net.intf.Interface;
-import org.onosproject.incubator.net.intf.InterfaceService;
+import org.onosproject.net.intf.Interface;
+import org.onosproject.net.intf.InterfaceService;
 import org.onosproject.incubator.net.routing.Route;
 import org.onosproject.incubator.net.routing.RouteStore;
 import org.onosproject.net.ConnectPoint;