ia64: add pci_get_legacy_ide_irq()

Add pci_get_legacy_ide_irq() identical to the one used by i386/x86_64.
Fixes amd74xx driver build on ia64 (bugzilla bug #6644).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

include/asm-ia64/pci.h

@@ -167,4 +167,10 @@ pcibios_select_root(struct pci_dev *pdev, struct resource *res)
 
 #define pcibios_scan_all_fns(a, b)	0
 
+#define HAVE_ARCH_PCI_GET_LEGACY_IDE_IRQ
+static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
+{
+	return channel ? 15 : 14;
+}
+
 #endif /* _ASM_IA64_PCI_H */