This patch is from John Rose <johnrose@austin.ibm.com>.

Upon DLPAR addition of a PCI Host Brige to a system with purely virtual I/O,
set pci_io_base as necessary.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>