PCI: Make pcie_update_link_speed() private

This interface:

  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);

is only used in drivers/pci/ and does not need to be seen by the rest of
the kernel.  Move it to drivers/pci/pci.h so it's private to the PCI
subsystem.

Link: https://lore.kernel.org/r/20190724233848.73327-8-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

@@ -299,6 +299,7 @@ u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
 			   enum pcie_link_width *width);
 void __pcie_print_link_status(struct pci_dev *dev, bool verbose);
 void pcie_report_downtraining(struct pci_dev *dev);
+void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
 
 /* Single Root I/O Virtualization */
 struct pci_sriov {

include/linux/pci.h

@@ -987,7 +987,6 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
 int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge);
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
 				int busnr);
-void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
 struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
 				 const char *name,
 				 struct hotplug_slot *hotplug);