usb: common: ulpi: Constify static attribute_group struct

It is never modified, so make them const to allow the compiler to
put it in read-only memory. Done with the help of coccinelle.

Signed-off-by: Rikard Falkeborn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/common/ulpi.c

···
 	NULL
 };
 
-static struct attribute_group ulpi_dev_attr_group = {
+static const struct attribute_group ulpi_dev_attr_group = {
 	.attrs = ulpi_dev_attrs,
 };