PCI: Add pci_reset_bridge_secondary_bus()

Move the secondary bus reset code from pci_parent_bus_reset() into its own
function.  Export it as we'll later be calling it from hotplug controllers
and elsewhere.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0fd1f15..35c1bc4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -924,6 +924,7 @@
 int __pci_reset_function(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
+void pci_reset_bridge_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
 int __must_check pci_assign_resource(struct pci_dev *dev, int i);
 int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);