[POWERPC] pseries: 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.

pseries platform changes.

Built for pseries_defconfig

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

arch/powerpc/platforms/pseries/firmware.c

@@ -68,7 +68,7 @@ firmware_features_table[FIRMWARE_MAX_FEATURES] = {
 void __init fw_feature_init(void)
 {
 	struct device_node *dn;
-	char *hypertas, *s;
+	const char *hypertas, *s;
 	int len, i;
 
 	DBG(" -> fw_feature_init()\n");