[ONOS-5232] bits enum class generation modifications and code refactoring.

Change-Id: I67fb31c586802e9cf682aa6e707475ad8fdc096f
diff --git a/generator/pom.xml b/generator/pom.xml
index 2781797..6db0cd0 100644
--- a/generator/pom.xml
+++ b/generator/pom.xml
@@ -39,6 +39,11 @@
             <artifactId>commons-io</artifactId>
             <version>2.4</version>
         </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.21</version>
+        </dependency>
     </dependencies>
 
     <build>