If we make all FEC (ethernet) addressing consistent across all ColdFire
family members then we will be able to remove the duplicated plaform data
and use a single setup for all.

So modify the ColdFire 523x FEC addressing so that:

. FECs are numbered from 0 up
. base addresses are absolute (not relative to MBAR peripheral register)
. use a common name for IRQs used
Signed-off-by: Greg Ungerer <gerg@uclinux.org>