85xx: Use CONFIG_SYS_{PCI*,RIO*}_MEM_PHYS for physical address on FSL boards

Use the _MEM_PHYS defines instead of _MEM_BUS for LAW and real address fields
of TLBs.  This is what we should have always been using from the start.

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