[POWERPC] 86xx/85xx: Move 8641 PCI-Express to arch/powerpc/sysdev/fsl_pcie.c.

This move sets the stage for the use of generic PCI Express
code in 85xx and 86xx parts from FSL.  Subsequent patches
for 8548 and 8544 will be able to use this shared code.

Signed-off-by: Jon Loeliger <jdl@freescale.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>