meta-ampere: Support virtual Ethernet over USB device

Implement systemd service to create an Ethernet over USB interface
for communication between CPU and BMC.

Tested:
1. Check usb0 ethernet interface in BMC console
root@mtjade:~# ifconfig usb0
usb0      Link encap:Ethernet  HWaddr DA:F7:E9:A3:5A:0C
          inet addr:192.168.0.10  Bcast:192.168.255.255  Mask:255.255.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:412 (412.0 B)
2. Check USB Ethernet device on Host Linux
$ lsusb | grep Ethernet
Bus 001 Device 004: ID 1d6b:0103 Linux Foundation NCM (Ethernet) Gadget

Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: Icb7c096df426233e8f2ee7318f2a1805f07ab3a7
6 files changed