media: usb: pulse8-cec: constify serio_device_id

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

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/pulse8-cec/pulse8-cec.c

@@ -731,7 +731,7 @@ static void pulse8_ping_eeprom_work_handler(struct work_struct *work)
 	mutex_unlock(&pulse8->config_lock);
 }
 
-static struct serio_device_id pulse8_serio_ids[] = {
+static const struct serio_device_id pulse8_serio_ids[] = {
 	{
 		.type	= SERIO_RS232,
 		.proto	= SERIO_PULSE8_CEC,