[POWERPC] cell: 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.

cell platform changes.

Built for cell_defconfig

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-powerpc/spu.h

@@ -106,7 +106,7 @@ struct spu_context;
 struct spu_runqueue;
 
 struct spu {
-	char *name;
+	const char *name;
 	unsigned long local_store_phys;
 	u8 *local_store;
 	unsigned long problem_phys;