[POWERPC] 86xx/85xx: Unify Freescale PCI Express memory map registers structure

Unify PCI Express memory map registers structure define
to arch/pwoerpc/sysdev/fsl_pcie.h for Freescale 85xx/86xx
processor family.

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