imx6: fix device-tree mac address assignment for ventana sky2/eth1

imx6: fix device-tree mac address assignment for ventana sky2/eth1

Some Ventana boards have a Marvell sky2 GigE controller as eth1 however
assigning the mac address through device-tree is difficult because the
PCI slot can move around depending on board configuration and slot population.

To work around this we add a patch to the sky2 driver to allow accessing its
mac address via a device-tree alias.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Pushpal Sidhu <psidhu@gateworks.com>
SVN-Revision: 48013