PCI: add pci_get_domain_bus_and_slot function

Added the pci_get_domain_and_slot_function which is analogous to
pci_get_bus_and_slot. It returns a pci_dev given a domain (segment) number,
bus number, and devnr. Like pci_get_bus_and_slot,
pci_get_domain_bus_and_slot holds a reference to the returned pci_dev.

Converted pci_get_bus_and_slot to a wrapper that calls
pci_get_domain_bus_and_slot with the domain hard-coded to 0.

This routine was patterned off code suggested by Bjorn Helgaas.

Acked-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9d646e6..86c31ac 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -636,7 +636,13 @@
 				unsigned int ss_vendor, unsigned int ss_device,
 				struct pci_dev *from);
 struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn);
-struct pci_dev *pci_get_bus_and_slot(unsigned int bus, unsigned int devfn);
+struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
+					    unsigned int devfn);
+static inline struct pci_dev *pci_get_bus_and_slot(unsigned int bus,
+						   unsigned int devfn)
+{
+	return pci_get_domain_bus_and_slot(0, bus, devfn);
+}
 struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
 int pci_dev_present(const struct pci_device_id *ids);