powerpc/dts/fsl: t2080rdb: reorder the Cortina PHY XFI lanes

According to the T2080RDB schematics, for the CS4315 PHY, the XFI 1 lane is
connected to SFP 2 and the XFI 2 lane is connected to SFP 1. Change the
device tree to reflect the correct PHY order and port association.

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>