db845c: Set Ethernet MAC address on boot

db845c development boards do not have unique
Ethernet MAC address. All boards share same
MAC address and it cause problems while
running CTS tests on db845c in a lab with
multiple db845c boards connected.

Set the Ethernet MAC address based on board's
unique serial number as a workaround for now.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: I1c5b63b7d6cbf5e55ac40980b5823cc6bb4f44d3
5 files changed