edac: mpc85xx fix build regression by removing unused debug code

Some unused, unsupported debug code existed in the mpc85xx EDAC driver
that resulted in a build failure when CONFIG_EDAC_DEBUG was defined:

  drivers/edac/mpc85xx_edac.c: In function 'mpc85xx_mc_err_probe':
  drivers/edac/mpc85xx_edac.c:1031: error: implicit declaration of function 'edac_mc_register_mcidev_debug'
  drivers/edac/mpc85xx_edac.c:1031: error: 'debug_attr' undeclared (first use in this function)
  drivers/edac/mpc85xx_edac.c:1031: error: (Each undeclared identifier is reported only once
  drivers/edac/mpc85xx_edac.c:1031: error: for each function it appears in.)

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>