Add CDC ECM support
CDC Ethernet support has not really implemented until now. There was USB class recognition but no handling of data transfer. Tested with
- VIVANCO USB3.0 Ethernet GigaBit Adapter, UGreen CM209
- Huawei E8372h-320 USB Surfstick (4G and WLAN Server) and Huawei E3372h-320
- Vodafone ZTE R216z
- Realtek USB 10/100 LAN
- ANKER A8352, CONCEPTRONIC DONNG06G, ABLEWE EA-02BK
- CoreChips SR9900 USB Ethernet Adapter