PCI: Make pci_bus_get(), pci_bus_put() private

These interfaces:

  struct pci_bus *pci_bus_get(struct pci_bus *bus);
  void pci_bus_put(struct pci_bus *bus);

are only used in drivers/pci/ and do not need to be seen by the rest of the
kernel.  Move them to drivers/pci/pci.h so they're private to the PCI
subsystem.

Link: https://lore.kernel.org/r/20190724233848.73327-7-skunberg.kelsey@gmail.com
Signed-off-by: Kelsey Skunberg <skunberg.kelsey@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/pci.h

@@ -274,6 +274,8 @@ bool pci_bus_clip_resource(struct pci_dev *dev, int idx);
 
 void pci_reassigndev_resource_alignment(struct pci_dev *dev);
 void pci_disable_bridge_window(struct pci_dev *dev);
+struct pci_bus *pci_bus_get(struct pci_bus *bus);
+void pci_bus_put(struct pci_bus *bus);
 
 /* PCIe link information */
 #define PCIE_SPEED2STR(speed) \

include/linux/pci.h

@@ -1282,8 +1282,6 @@ int pci_request_selected_regions_exclusive(struct pci_dev *, int, const char *);
 void pci_release_selected_regions(struct pci_dev *, int);
 
 /* drivers/pci/bus.c */
-struct pci_bus *pci_bus_get(struct pci_bus *bus);
-void pci_bus_put(struct pci_bus *bus);
 void pci_add_resource(struct list_head *resources, struct resource *res);
 void pci_add_resource_offset(struct list_head *resources, struct resource *res,
 			     resource_size_t offset);