sparc64: Refactor OBP cpu scanning code using an iterator.

With feedback from Sam Ravnborg.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
index 900d447..1b15212 100644
--- a/arch/sparc/include/asm/prom.h
+++ b/arch/sparc/include/asm/prom.h
@@ -86,6 +86,7 @@
 #endif
 
 extern void prom_build_devicetree(void);
+extern void of_populate_present_mask(void);
 
 /* Dummy ref counting routines - to be implemented later */
 static inline struct device_node *of_node_get(struct device_node *node)