HID: wacom: Constify attribute_groups

These are never modified, so make them const to allow the compiler to put
them in read-only memory. It also allows the compiler to shrink the
resulting module with ~900 bytes, test-built with gcc 10.2 on x86_64.

   text    data     bss     dec     hex filename
 204377   42832     576  247785   3c7e9 drivers/hid/wacom_old.ko
 204240   42064     576  246880   3c460 drivers/hid/wacom_new.ko

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

@@ -1173,7 +1173,7 @@ static struct attribute *cintiq_led_attrs[] = {
 	NULL
 };
 
-static struct attribute_group cintiq_led_attr_group = {
+static const struct attribute_group cintiq_led_attr_group = {
 	.name = "wacom_led",
 	.attrs = cintiq_led_attrs,
 };
@@ -1194,7 +1194,7 @@ static struct attribute *intuos4_led_attrs[] = {
 	NULL
 };
 
-static struct attribute_group intuos4_led_attr_group = {
+static const struct attribute_group intuos4_led_attr_group = {
 	.name = "wacom_led",
 	.attrs = intuos4_led_attrs,
 };
@@ -1205,7 +1205,7 @@ static struct attribute *intuos5_led_attrs[] = {
 	NULL
 };
 
-static struct attribute_group intuos5_led_attr_group = {
+static const struct attribute_group intuos5_led_attr_group = {
 	.name = "wacom_led",
 	.attrs = intuos5_led_attrs,
 };
@@ -1216,13 +1216,13 @@ static struct attribute *generic_led_attrs[] = {
 	NULL
 };
 
-static struct attribute_group generic_led_attr_group = {
+static const struct attribute_group generic_led_attr_group = {
 	.name = "wacom_led",
 	.attrs = generic_led_attrs,
 };
 
 struct wacom_sysfs_group_devres {
-	struct attribute_group *group;
+	const struct attribute_group *group;
 	struct kobject *root;
 };
 
@@ -1238,7 +1238,7 @@ static void wacom_devm_sysfs_group_release(struct device *dev, void *res)
 
 static int __wacom_devm_sysfs_create_group(struct wacom *wacom,
 					   struct kobject *root,
-					   struct attribute_group *group)
+					   const struct attribute_group *group)
 {
 	struct wacom_sysfs_group_devres *devres;
 	int error;
@@ -1264,7 +1264,7 @@ static int __wacom_devm_sysfs_create_group(struct wacom *wacom,
 }
 
 static int wacom_devm_sysfs_create_group(struct wacom *wacom,
-					 struct attribute_group *group)
+					 const struct attribute_group *group)
 {
 	return __wacom_devm_sysfs_create_group(wacom, &wacom->hdev->dev.kobj,
 					       group);
@@ -1847,7 +1847,7 @@ static struct attribute *remote##SET_ID##_serial_attrs[] = {		\
 	&remote##SET_ID##_mode_attr.attr,				\
 	NULL								\
 };									\
-static struct attribute_group remote##SET_ID##_serial_group = {		\
+static const struct attribute_group remote##SET_ID##_serial_group = {	\
 	.name = NULL,							\
 	.attrs = remote##SET_ID##_serial_attrs,				\
 }