Adding Zyxel to allowed list of vendors

Change-Id: If0282c63fcb4f57f607d165ca7149cec8ddbbee8
diff --git a/voltha-adapter-openonu/values.yaml b/voltha-adapter-openonu/values.yaml
index bd30a4c..6c35d1b 100644
--- a/voltha-adapter-openonu/values.yaml
+++ b/voltha-adapter-openonu/values.yaml
@@ -104,6 +104,7 @@
   - ADTN
   - ARCA
   - AVMG
+  - ZYWN
 
 # Expose the golang pprof webserver, if enabled
 profiler: