[POWERPC] Create common fsl pci/e files based on 86xx platforms

Move
arch/powerpc/platforms/86xx/pci.c -> arch/powerpc/sysdev/fsl_pci.c
arch/powerpc/sysdev/fsl_pcie.h -> arch/powerpc/sysdev/fsl_pci.h
as the base to unify 83xx/85xx/86xx pci and pcie.

Add CONFIG_FSL_PCI to build fsl_pci.c for Freescale pci and pcie option.
The code still works for 86xx platforms.

Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>