[ONOS-4711] Move YANG data types to data types to remove dependency

Change-Id: I2297fc1fa69c7609765fc970d5614447db8e9f88
diff --git a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
index 0c717a6..b01ff63 100644
--- a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
+++ b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangLeaf.java
@@ -62,7 +62,7 @@
  */
 public class YangLeaf
         implements YangCommonInfo, Parsable, Cloneable, Serializable,
-        YangMustHolder, YangIfFeatureHolder, YangWhenHolder {
+        YangMustHolder, YangIfFeatureHolder, YangWhenHolder, YangDataNode {
 
     private static final long serialVersionUID = 806201635L;