OIntroduced POST and GET rest apis for adding and fetching OLT Information

Change-Id: I997093581c22cdfe8211caced804d327e29834c8
diff --git a/voltha-go-controller/onos_nbi/models.go b/voltha-go-controller/onos_nbi/models.go
index ea9c19b..5f8f923 100644
--- a/voltha-go-controller/onos_nbi/models.go
+++ b/voltha-go-controller/onos_nbi/models.go
@@ -482,6 +482,14 @@
 	Subscribers []SubscriberInfo `json:"subscribers"`
 }
 
+type OltFlowServiceConfig struct {
+	OltFlowService app.OltFlowService `json:"oltFlowService"`
+}
+
+type DeviceConfigPayload struct {
+	DeviceConfig *app.DeviceConfig `json:"deviceConfig"`
+}
+
 func ConvertFlowToFlowEntry(subFlow *of.VoltSubFlow) FlowEntry {
 	var flowEntry FlowEntry
 	flowEntry.Flows = []Flow{}
@@ -688,10 +696,6 @@
 	Protocol          string `json:"protocol"`
 }
 
-type OltFlowServiceConfig struct {
-	OltFlowService app.OltFlowService `json:"oltflowservice"`
-}
-
 func convertVoltDeviceToDevice(voltDevice *app.VoltDevice) Device {
 	var device Device