usb: phy-tahvo: constify attribute_group structures.

attribute_group are not supposed to change at runtime. All functions
working with attribute_group provided by <linux/sysfs.h> work with
const attribute_group. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>

Author: ArvindYadavCs

drivers/usb/phy/phy-tahvo.c

@@ -326,7 +326,7 @@ static struct attribute *tahvo_attributes[] = {
 	NULL
 };
 
-static struct attribute_group tahvo_attr_group = {
+static const struct attribute_group tahvo_attr_group = {
 	.attrs = tahvo_attributes,
 };