Provide stubs for more PCI bus/slot functions when CONFIG_PCI=n.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>