rb5: Set Ethernet MAC address on boot

Just like DB845c devboards, RB5 do not have unique Ethernet
MAC addresses. All the boards share the same MAC address and
it cause problems while running CTS tests in the lab with
multiple RB5 boards connected.

So set the Ethernet MAC address based on board's unique
serial number as we do for DB845c.

Change-Id: I103e18c34a34c4d36d6cc71e7a7f964bcd0417b4
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
2 files changed