[POWERPC] Fix 8xx compile failure

  CC      arch/powerpc/sysdev/commproc.o
arch/powerpc/sysdev/fsl_soc.c: In function fsl_pcmcia_of_init:
arch/powerpc/sysdev/fsl_soc.c:1109: error: implicit declaration of function of_platform_device_create

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>