VOL-2916 Use cached values instead of childDevice query

Change-Id: Ia317badd71343d6b4d2f613da08deb286fbfbd61
diff --git a/internal/pkg/core/device_handler.go b/internal/pkg/core/device_handler.go
index 6b7ca7e..f019f10 100644
--- a/internal/pkg/core/device_handler.go
+++ b/internal/pkg/core/device_handler.go
@@ -2149,3 +2149,9 @@
 	}
 	return 0
 }
+
+// StoreOnuDevice stores the onu parameters to the local cache.
+func (dh *DeviceHandler) StoreOnuDevice(onuDevice *OnuDevice) {
+	onuKey := dh.formOnuKey(onuDevice.intfID, onuDevice.onuID)
+	dh.onus.Store(onuKey, onuDevice)
+}