[PATCH] ppc iomem annotations: ->io_base_virt

* ->io_base_virt in struct pci_controller is iomem pointer.  Marked as such.
  Most of the places that used it are already annotated to expect iomem.
* places that did gratitious (and wrong) casts a-la
	isa_io_base = (unsigned long)ioremap(...);
	hose->io_base_virt = (void *)isa_io_base;
  turned into
	hose->io_base_virt = ioremap(...);
	isa_io_base = (unsigned long)hose->io_base_virt;
* pci_bus_io_base() annotated as returning iomem pointer.

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>