Fixes several oopsen in the SA-1111 "fake" PCI support

Complete re-write of the SA-1111 DMA bug "bounce buffer" workaround.

Merge latest drivers/pci/pool.c into mach-sa1100/pcipool.c (pool
allocation debugging follows CONFIG_DEBUG_SLAB a la drivers/pci/pool.c)

/arch/arm/mach-sa1100/pcipool.h can be deleted
(unrelated: /arch/arm/mach-sa1100/sa1111-ohci.c can be deleted)

Applies to 2.5.30-rmk1.  Should be back ported to 2.4 as the existing
SA-1111 bounce buffer code is broken.

(This patch is *required* for the OHCI HCD driver that is part of 2.5.21+.)