[POWERPC] 85xx: Add device nodes for error reporting devices used by EDAC

Adding memory-controller and l2-cache-controller entries to be used by EDAC
as of_devices for MPC8540 ADS, MPC8548 CDS, and MPC8560 ADS.

Also fixed up the size of the PCI node on MPC8560 ADS.

Signed-off-by: Dave Jiang <djiang@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>