[ONOS-4753] Identity/identityref implementation and UT

Change-Id: I40148fa228465555be3bdf410cc294ffc0f34c18
diff --git a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangDerivedInfo.java b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangDerivedInfo.java
index 640aa64..1661d96 100644
--- a/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangDerivedInfo.java
+++ b/utils/yangutils/datamodel/src/main/java/org/onosproject/yangutils/datamodel/YangDerivedInfo.java
@@ -334,7 +334,7 @@
                     return RESOLVED;
                 }
             }
-        } else if (baseType.getDataType() == LEAFREF) {
+        } else if ((baseType.getDataType() == LEAFREF) || (baseType.getDataType() == IDENTITYREF)) {
             setEffectiveBuiltInType(baseType.getDataType());
             return RESOLVED;
         } else {