[VOL-2404] : RW-Core changes for handling OLT Reboot Scenario

- When the OLT's connection status goes from REACHABLE to UNREACHABLE
  in ENABLED/DISABLED admin state, delete all the logical ports,
  child devices, logical device and device flows.

- When OLT's connection status becomes reachable again, child devices,
  ports will be re-discovered again. The logical device will be recreated
  again.

- Will not handle the case where OLT goes UNREACHABLE when OLT is disabled
  as part of voltha2.3 release

Change-Id: I34c0c538b44afa19e889e9631f0a738060a58fef
diff --git a/rw_core/mocks/device_manager.go b/rw_core/mocks/device_manager.go
index b3d63cb..7fb2983 100644
--- a/rw_core/mocks/device_manager.go
+++ b/rw_core/mocks/device_manager.go
@@ -78,6 +78,16 @@
 	return nil
 }
 
+// DeleteAllLogicalPorts -
+func (dm *DeviceManager) DeleteAllLogicalPorts(ctx context.Context, cDevice *voltha.Device, pDevice *voltha.Device) error {
+	return nil
+}
+
+// DeleteAllDeviceFlows -
+func (dm *DeviceManager) DeleteAllDeviceFlows(ctx context.Context, cDevice *voltha.Device, pDevice *voltha.Device) error {
+	return nil
+}
+
 // RunPostDeviceDelete -
 func (dm *DeviceManager) RunPostDeviceDelete(ctx context.Context, cDevice *voltha.Device, pDevice *voltha.Device) error {
 	return nil