PCI: drivers/pci/: remove unused exports

This patch removes the following unused exports:
- remove the following unused EXPORT_SYMBOL's:
 - pci-acpi.c: pci_osc_support_set
 - proc.c: pci_proc_detach_bus
- remove the following unused EXPORT_SYMBOL_GPL's:
  - bus.c: pci_walk_bus
  - probe.c: pci_create_bus
  - setup-res.c: pci_claim_resource

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>