Fix Maple PATA IRQ assignment.

On the Maple board, the AMD8111 IDE is in legacy mode... except that it
appears on IRQ 20 instead of IRQ 15. For drivers/ide this was handled by
the architecture's "pci_get_legacy_ide_irq()" function, but in libata we
just hard-code the numbers 14 and 15.

This patch provides asm-powerpc/libata-portmap.h which maps the IRQ as
appropriate, having added a pci_dev argument to the
ATA_{PRIM,SECOND}ARY_IRQ macros.

There's probably a better way to do this -- especially if we observe
that the _only_ case in which this seemingly-generic
"pci_get_legacy_ide_irq()" function returns anything other than 14 and
15 for primary and secondary respectively is the case of the AMD8111 on
the Maple board -- couldn't we handle that with a special case in the
pata_amd driver, or perhaps with a PCI quirk for Maple to switch it into
native mode during early boot and assign resources properly?

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/asm-powerpc/libata-portmap.h b/include/asm-powerpc/libata-portmap.h
new file mode 100644
index 0000000..4d85180
--- /dev/null
+++ b/include/asm-powerpc/libata-portmap.h
@@ -0,0 +1,12 @@
+#ifndef __ASM_POWERPC_LIBATA_PORTMAP_H
+#define __ASM_POWERPC_LIBATA_PORTMAP_H
+
+#define ATA_PRIMARY_CMD	0x1F0
+#define ATA_PRIMARY_CTL	0x3F6
+#define ATA_PRIMARY_IRQ(dev)	pci_get_legacy_ide_irq(dev, 0)
+
+#define ATA_SECONDARY_CMD	0x170
+#define ATA_SECONDARY_CTL	0x376
+#define ATA_SECONDARY_IRQ(dev)	pci_get_legacy_ide_irq(dev, 1)
+
+#endif