ACPI: simplify acpi_pci_irq_add_prt() API

A PCI domain cannot change as you descend down subordinate buses, which
makes the 'segment' argument to acpi_pci_irq_add_prt() useless.

Change the interface to take a struct pci_bus *, from whence we can derive
the bus number and segment. Reducing the number of arguments makes life
simpler for callers.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 2740a28..686a960 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -91,7 +91,7 @@
 
 /* ACPI PCI Interrupt Routing (pci_irq.c) */
 
-int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus);
+int acpi_pci_irq_add_prt(acpi_handle handle, struct pci_bus *bus);
 void acpi_pci_irq_del_prt(int segment, int bus);
 
 /* ACPI PCI Device Binding (pci_bind.c) */