Depend on released ONOS 2.2.1 artifacts

Change-Id: Idf371fa86a8a26a85aa91fe2c2a54ee19193f485
diff --git a/pom.xml b/pom.xml
index 4a3c958..3779679 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,7 +22,7 @@
     <parent>
         <groupId>org.onosproject</groupId>
         <artifactId>onos-dependencies</artifactId>
-        <version>2.2.1-b4</version>
+        <version>2.2.1</version>
     </parent>
 
     <groupId>org.opencord</groupId>