[PATCH] fix via586 irq routing for pirq 5

Fix interrupt routing for via 586 bridges.  pirq can be 5 which needs to be
mapped to INTD.  But currently the access functions can handle only pirq
1-4.  this is similar to the other via chipsets where pirq 4 and 5 are both
mapped to INTD.  Fixes bugzilla #7490

Cc: Daniel Paschka <monkey20181@gmx.net>
Cc: Adrian Bunk <bunk@susta.de>
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

arch/i386/pci/irq.c

@@ -255,13 +255,13 @@ static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, i
  */
 static int pirq_via586_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
 {
-	static const unsigned int pirqmap[4] = { 3, 2, 5, 1 };
+	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
 	return read_config_nybble(router, 0x55, pirqmap[pirq-1]);
 }
 
 static int pirq_via586_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
 {
-	static const unsigned int pirqmap[4] = { 3, 2, 5, 1 };
+	static const unsigned int pirqmap[5] = { 3, 2, 5, 1, 1 };
 	write_config_nybble(router, 0x55, pirqmap[pirq-1], irq);
 	return 1;
 }