Expose c_tag and s_tag configs in bbsim helm chart

Change-Id: I05913558ce92d5b697301408219a9bbd5165b312
diff --git a/bbsim/values.yaml b/bbsim/values.yaml
index 44ef698..9136b44 100644
--- a/bbsim/values.yaml
+++ b/bbsim/values.yaml
@@ -23,6 +23,8 @@
 auth: false
 dhcp: false
 delay: 200
+c_tag: 900
+s_tag: 900
 
 # TODO read this values in the config
 olt_tcp_port: 50060