8xxx: Refactored common cpu specific code for 85xx/86xx into one file.

Removed same code pieces from cpu/mpc85xx/cpu.c and cpu/mpc86xx/cpu.c
and moved to cpu/mpc8xxx/cpu.c(new file)

Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
5 files changed