[MIPS] PCI: Make dev pointer argument of pcibios_map_irq const.

This is to break the code of people who think they are supposed to scribble
into the pci device structure - it's off limits.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/pci.h b/include/asm-mips/pci.h
index 3eea3ba..a59d547 100644
--- a/include/asm-mips/pci.h
+++ b/include/asm-mips/pci.h
@@ -56,7 +56,7 @@
 /*
  * board supplied pci irq fixup routine
  */
-extern int pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin);
+extern int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin);
 
 
 /* Can be used to override the logic in pci_scan_bus for skipping