ARM: dts: vf-colibri: alias the primary FEC as ethernet0

ARM: dts: vf-colibri: alias the primary FEC as ethernet0

The Vybrid based Colibri modules provide a on-module PHY which is
connected to the second FEC instance FEC1. Since the on-module
Ethernet port is considered as primary ethernet interface, alias
fec1 as ethernet0. This also makes sure that the first MAC address
provided by the boot loader gets assigned to the FEC instance used
for the on-module PHY.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>