[POWERPC] Constify & voidify get_property()

Now that get_property() returns a void *, there's no need to cast its
return value. Also, treat the return value as const, so we can
constify get_property later.

powerpc core changes.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/vio.h b/include/asm-powerpc/vio.h
index dc9bd101..4b51d42 100644
--- a/include/asm-powerpc/vio.h
+++ b/include/asm-powerpc/vio.h
@@ -46,8 +46,8 @@
  */
 struct vio_dev {
 	struct iommu_table *iommu_table;     /* vio_map_* uses this */
-	char *name;
-	char *type;
+	const char *name;
+	const char *type;
 	uint32_t unit_address;
 	unsigned int irq;
 	struct device dev;