m68knommu: fix fec setup warning for ColdFire 5271 builds

Building for the ColdFire 5271 produces the following warning:

arch/m68k/coldfire/m527x.c: In function ‘m527x_fec_init’:
arch/m68k/coldfire/m527x.c:95:6: warning: unused variable ‘par’

Fix it by moving the definition of par inside the 5271 conditional code.

Reported-by: ertheb <3rth3bnospam@ethe.fr>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>