[ 3050 ] Fixing cut and paste error in voltha.proto.

This commit is an amendment to the previous commit with the
following changes:

1) Simplify the gRPC API to replace the activate_olt and re_enable apis
   with only one enable api.  Note the adapter interface remains
   unchanged to keep the flexibility of operations between different
   device adapters.
2) Small changes following the initial code review

This commit consits of the following updates:
1) Support for the following config changes:
      1a) Reboot of an OLT/ONU
      1b) Deletion of an OLT/ONU
      1c) Disabling of an OLT/ONU
      1d) Re-enabling of an OLT/ONU

2) Corresponding APIs are added to the voltha.proto file

3) The adapter interface has been augmented with the above
   APIs

4) The ponsim_olt and ponsim_onu adapters have been updated to
   implement the above APIs

TODOs:
1) Existing flows on the ponsim devices have not been updated
to reflect the above changes.
2) ponsim needs to be augmented to support the above APIs
3) integration tests

The above will be addressed in a separate commit

Change-Id: Ia7af7d773517df269cdc2b0c629d5ef8f1fb6e3a
diff --git a/voltha/adapters/interface.py b/voltha/adapters/interface.py
index 4111735..c7016d1 100644
--- a/voltha/adapters/interface.py
+++ b/voltha/adapters/interface.py
@@ -89,11 +89,45 @@
         :return: (Deferred) Shall be fired to acknowledge abandonment.
         """
 
-    def deactivate_device(device):
+    def disable_device(device):
         """
-        Called if the device is to be deactivate based on a NBI call.
+        This is called when a previously enabled device needs to be disabled
+        based on a NBI call.
         :param device: A Voltha.Device object.
-        :return: (Deferred) Shall be fired to acknowledge deactivation.
+        :return: (Deferred) Shall be fired to acknowledge disabling the device.
+        """
+
+    def reenable_device(device):
+        """
+        This is called when a previously disabled device needs to be enabled
+        based on a NBI call.
+        :param device: A Voltha.Device object.
+        :return: (Deferred) Shall be fired to acknowledge re-enabling the
+        device.
+        """
+
+    def reboot_device(device):
+        """
+        This is called to reboot a device based on a NBI call.  The admin
+        state of the device will not change after the reboot
+        :param device: A Voltha.Device object.
+        :return: (Deferred) Shall be fired to acknowledge the reboot.
+        """
+
+    def delete_device(device):
+        """
+        This is called to delete a device from the PON based on a NBI call.
+        If the device is an OLT then the whole PON will be deleted.
+        :param device: A Voltha.Device object.
+        :return: (Deferred) Shall be fired to acknowledge the deletion.
+        """
+
+    def get_device_details(device):
+        """
+        This is called to get additional device details based on a NBI call.
+        :param device: A Voltha.Device object.
+        :return: (Deferred) Shall be fired to acknowledge the retrieval of
+        additional details.
         """
 
     def update_flows_bulk(device, flows, groups):
@@ -151,8 +185,8 @@
         :return: None
         """
 
-    # TODO work in progress
-    # ...
+        # TODO work in progress
+        # ...
 
 
 class IAdapterAgent(Interface):