powerpc/mpc832x_rdb: fix swapped ethernet ids

ethernet0 (called FSL UEC0 in U-Boot) should be enet1 (UCC3/eth1), and
ethernet1 should be enet0 (UCC2/eth0), to be consistent with U-Boot so
that the interfaces do not swap addresses when control passes from
U-Boot to the kernel.

Signed-off-by: Michael Barkowski <michael.barkowski@freescale.com>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>