powerpc: mpc8xx: CPM parameter RAM can be anywhere

With relocation, CPM parameter RAM can be anywhere in the
dual port RAM, so don't split dual port RAM.

Remove dparam and dparam16 members of struct comm_proc

PROFF_XXX become offsets from the start of dual port RAM,
then they are now consistant with the offsets in RPBASE
registers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

powerpc: mpc8xx: Change CONFIG_8xx to CONFIG_MPC8xx

CONFIG_8xx doesn't mean much outside of arch/powerpc/
This patch renames it CONFIG_MPC8xx just like CONFIG_MPC85xx etc ...
It also renames 8xx_immap.h to immap_8xx.h to be consistent with
other file names.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

powerpc: mpc8xx: Change CONFIG_8xx to CONFIG_MPC8xx

CONFIG_8xx doesn't mean much outside of arch/powerpc/
This patch renames it CONFIG_MPC8xx just like CONFIG_MPC85xx etc ...
It also renames 8xx_immap.h to immap_8xx.h to be consistent with
other file names.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>