PCI: Provide a default pcibios_update_irq()

Most architectures implement this in exactly the same way. Instead of
having each architecture duplicate this function, provide a single
implementation in the core and make it a weak symbol so that it can be
overridden on architectures where it is required.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/m68k/kernel/pcibios.c

@@ -87,11 +87,6 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 	return 0;
 }
 
-void pcibios_update_irq(struct pci_dev *dev, int irq)
-{
-	pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
-}
-
 void __devinit pcibios_fixup_bus(struct pci_bus *bus)
 {
 	struct pci_dev *dev;