[POWERPC] Fix copy'n'paste typo in commproc.c

[POWERPC] Fix copy'n'paste typo in commproc.c

The powerpc version of commproc.c exports cpm_dpram_addr twice
and cpm_dpram_phys not at all due to a typo. This patch fixes this
problem.

CC      arch/powerpc/sysdev/commproc.o
arch/powerpc/sysdev/commproc.c:398: error: redefinition of '__kcrctab_cpm_dpram_addr'
arch/powerpc/sysdev/commproc.c:392: error: previous definition of '__kcrctab_cpm_dpram_addr' was here
arch/powerpc/sysdev/commproc.c:398: error: redefinition of '__kstrtab_cpm_dpram_addr'
arch/powerpc/sysdev/commproc.c:392: error: previous definition of '__kstrtab_cpm_dpram_addr' was here
arch/powerpc/sysdev/commproc.c:398: error: redefinition of '__ksymtab_cpm_dpram_addr'
arch/powerpc/sysdev/commproc.c:392: error: previous definition of '__ksymtab_cpm_dpram_addr' was here
make[1]: *** [arch/powerpc/sysdev/commproc.o] Error 1
make: *** [arch/powerpc/sysdev] Error 2

Signed-off-by: Jochen Friedrich <jochen@scram.de>