[POWERPC] Kill non-existent symbols from ksyms and commproc.h

Remove exports of __res and cpm_install_handler/cpm_free_handler.  Remove
cpm_install_handler/cpm_free_handler from the commproc.h as well.  Both
were used for ARCH=ppc and aren't defined for ARCH=powerpc.

CC      arch/powerpc/kernel/ppc_ksyms.o
arch/powerpc/kernel/ppc_ksyms.c:180: error: '__res' undeclared here (not in a function)
arch/powerpc/kernel/ppc_ksyms.c:180: warning: type defaults to 'int' in declaration of '__res'
make[1]: *** [arch/powerpc/kernel/ppc_ksyms.o] Error 1
make: *** [arch/powerpc/kernel] Error 2

LD      .tmp_vmlinux1
arch/powerpc/kernel/built-in.o:(__ksymtab+0x198): undefined reference to `cpm_free_handler'
arch/powerpc/kernel/built-in.o:(__ksymtab+0x1a0): undefined reference to `cpm_install_handler'
make: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>