Add support for the currituck 476 platform from IBM (v2)

[Tony Breeds]

Patches 1 to 3
        Modify the 44x PCI code to work with 476fpe/currituck.
Patch 4
       	Is an old patch by Christoph Egger that fell through the cracks somehow.
Patches 5 and 6
        Modify the bootwrapper to handle 476fpe/currituck
Patch 7
       	The SoC support.
Patch 8
       	The currituck board support.