[POWERPC] FSL: Rework PCI/PCIe support for 85xx/86xx

The current PCI code for Freescale 85xx/86xx was treating the virtual
P2P PCIe bridge as a transparent bridge.  Rather than doing that fixup
the virtual P2P bridge by copying the resources from the PHB.

Also, fixup a bit of the code for dealing with resource_size_t being
64-bits and how we set ATMU registers for >4G.

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