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/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index b5c72e4..7ec3041a 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -573,7 +573,7 @@
 	.is_visible =	dev_string_attrs_are_visible,
 };
 
-struct attribute_group *usb_device_groups[] = {
+const struct attribute_group *usb_device_groups[] = {
 	&dev_attr_grp,
 	&dev_string_attr_grp,
 	NULL
@@ -799,7 +799,7 @@
 	.is_visible =	intf_assoc_attrs_are_visible,
 };
 
-struct attribute_group *usb_interface_groups[] = {
+const struct attribute_group *usb_interface_groups[] = {
 	&intf_attr_grp,
 	&intf_assoc_attr_grp,
 	NULL