VOL-291 : PON simulator refactoring for cluster integration

- Added ponsim build target in Makefile
- Added new option to vcore to select comm type with ponsim
- Modified all proto files to include destination go package

Amendments:

- Clean up based on review comments
- Properly close GRPC connections in ponsim_olt adapter
- Added voltha namespace to some k8s templates

Change-Id: I2f349fa7b3550a8a8cc8fc676cc896f33fbb9372
diff --git a/ponsim/v2/grpc/grpc_security.go b/ponsim/v2/grpc/grpc_security.go
new file mode 100644
index 0000000..6dab468
--- /dev/null
+++ b/ponsim/v2/grpc/grpc_security.go
@@ -0,0 +1,7 @@
+package grpc
+
+type GrpcSecurity struct {
+	KeyFile  string
+	CertFile string
+	CaFile   string
+}