[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/coreif/device_manager_if.go b/rw_core/coreif/device_manager_if.go
index a3f65cf..f828ab0 100644
--- a/rw_core/coreif/device_manager_if.go
+++ b/rw_core/coreif/device_manager_if.go
@@ -39,4 +39,6 @@
 	RunPostDeviceDelete(ctx context.Context, curr *voltha.Device, prev *voltha.Device) error
 	ChildDeviceLost(ctx context.Context, curr *voltha.Device, prev *voltha.Device) error
 	DeleteAllUNILogicalPorts(ctx context.Context, curr *voltha.Device, prev *voltha.Device) error
+	DeleteAllLogicalPorts(ctx context.Context, curr *voltha.Device, prev *voltha.Device) error
+	DeleteAllDeviceFlows(ctx context.Context, curr *voltha.Device, prev *voltha.Device) error
 }