PS3 system bus patches for 2.6.21

Paul,

This is an additional small set of patches for 2.6.21 that should apply on top of my previous set of 16.

Patches 1 & 2 mainly just move code to the ps3 platform directory as requested by Ben and Christoph. Patches 3 & 4 fix USB mass storage.

[PATCH 1/4] PS3: Move system bus to platform directory [PATCH 2/4] PS3: Move vuart declarations to ps3.h [PATCH 3/4] PS3: Fix DMA scatter-gather [PATCH 4/4] PS3: Enable USB mass storage

-Geoff