[POWERPC] bootwrapper: Add dt_xlate_reg(), and use it to find serial registers.

dt_xlate_reg() uses the ranges properties of a node's parentage to find
the absolute physical address of the node's registers.

The ns16550 driver uses this when no virtual-reg property is found.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 8008d61..fbd9030 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -82,6 +82,8 @@
 void *simple_alloc_init(char *base, u32 heap_size, u32 granularity,
 		u32 max_allocs);
 extern void flush_cache(void *, unsigned long);
+int dt_xlate_reg(void *node, int res, unsigned long *addr,
+                 unsigned long *size);
 
 static inline void *finddevice(const char *name)
 {