VOL-762 onu delete/disable in openolt drivers

Receives grpc command from voltha for Deactivate and Delete onu.
For Deactivate, upstream DBA tm_sched is cleared and onu device is
set to admin down.
For Delete, the onu device subcriber terminal session is cleared
initiating re-discovery by voltha.

Change-Id: I91862a109b58ae823b609b5477b9d82fcf868b5b
diff --git a/protos/openolt.proto b/protos/openolt.proto
index e13cc83..1140748 100644
--- a/protos/openolt.proto
+++ b/protos/openolt.proto
@@ -25,6 +25,20 @@
         };
     }
 
+    rpc DeactivateOnu(Onu) returns (Empty) {
+        option (google.api.http) = {
+          post: "/v1/DisableOnu"
+          body: "*"
+        };
+    }
+
+    rpc DeleteOnu(Onu) returns (Empty) {
+        option (google.api.http) = {
+          post: "/v1/DeleteOnu"
+          body: "*"
+        };
+    }
+
     rpc OmciMsgOut(OmciMsg) returns (Empty) {
         option (google.api.http) = {
           post: "/v1/OmciMsgOut"