octeon: add support for Ubiquiti UniFi Security Gateway
Ubiquiti UniFi Security Gateway (USG) is largely identical to
the EdgeRouter Lite (ERLite-3) apart from a different board ID
and two dome leds.
Device data (from WikiDev):
CPU: Cavium Octeon Plus CN5020 @500MHz 2-cores
Ethernet: 3x Atheros AR8035-A GbE PHY's
Flash: On-board 4MB Flash
Storage: Internal 3.8GB USB Flash (Kingston ID) drive
w/ 1.5GB free for use occupies single internal USB port.
Serial: 1x RJ45 port on front panel. 115200, 8N1
Buttons: 1x Reset
Flash instructions are identical to EdgeRouter Lite.
Signed-off-by: Clemens Hopfer <openwrt@wireloss.net>