driver model: constify attribute groups

Let attribute group vectors be declared "const".  We'd
like to let most attribute metadata live in read-only
sections... this is a start.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c
index 9215fbb..a4b2c57 100644
--- a/drivers/s390/net/netiucv.c
+++ b/drivers/s390/net/netiucv.c
@@ -2159,7 +2159,7 @@
 	.attrs = netiucv_drv_attrs,
 };
 
-static struct attribute_group *netiucv_drv_attr_groups[] = {
+static const struct attribute_group *netiucv_drv_attr_groups[] = {
 	&netiucv_drv_attr_group,
 	NULL,
 };