[POWERPC] Make OF irq map code detect more error cases

Device-tree bugs on js20 with some versions of SLOF were causing the
interrupt for IDE to not be parsed correctly and fail to boot. This
patch adds a bit more sanity checking to the parser to detect some of
those errors and fail instead of returning bogus information.  The
powerpc PCI code can then trigger a fallback that works on those
machines.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/prom.h b/include/asm-powerpc/prom.h
index b095a28..d0fa1b9 100644
--- a/include/asm-powerpc/prom.h
+++ b/include/asm-powerpc/prom.h
@@ -276,6 +276,7 @@
  * of_irq_map_raw - Low level interrupt tree parsing
  * @parent:	the device interrupt parent
  * @intspec:	interrupt specifier ("interrupts" property of the device)
+ * @ointsize:   size of the passed in interrupt specifier
  * @addr:	address specifier (start of "reg" property of the device)
  * @out_irq:	structure of_irq filled by this function
  *
@@ -288,7 +289,8 @@
  *
  */
 
-extern int of_irq_map_raw(struct device_node *parent, u32 *intspec, u32 *addr,
+extern int of_irq_map_raw(struct device_node *parent, u32 *intspec,
+			  u32 ointsize, u32 *addr,
 			  struct of_irq *out_irq);