[POWERPC] CPM: Rename commproc to cpm1 and cpm2_common.c to cpm2.c

Rename commproc.[ch] to cpm1.[ch] to be more consistent with cpm2. Also
rename cpm2_common.c to cpm2.c as suggested by Scott Wood. Adjust the
includes accordingly.

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>