Adding onos-of-drivers module.
Adding pmd resources to the top-level build... not working yet.
diff --git a/of/pom.xml b/of/pom.xml
index 465440d..5a030f4 100644
--- a/of/pom.xml
+++ b/of/pom.xml
@@ -19,6 +19,7 @@
     <modules>
         <module>api</module>
         <module>ctl</module>
+        <module>drivers</module>
     </modules>
 
     <build>