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/input/input.c b/drivers/input/input.c
index 7c237e6..851791d 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1144,7 +1144,7 @@
 	.attrs	= input_dev_caps_attrs,
 };
 
-static struct attribute_group *input_dev_attr_groups[] = {
+static const struct attribute_group *input_dev_attr_groups[] = {
 	&input_dev_attr_group,
 	&input_dev_id_attr_group,
 	&input_dev_caps_attr_group,