media: radio: constify pnp_device_id

pnp_device_id are not supposed to change at runtime. All functions
working with pnp_device_id provided by <linux/pnp.h> work with
const pnp_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/radio/radio-cadet.c

@@ -528,7 +528,7 @@ static const struct v4l2_ctrl_ops cadet_ctrl_ops = {
 
 #ifdef CONFIG_PNP
 
-static struct pnp_device_id cadet_pnp_devices[] = {
+static const struct pnp_device_id cadet_pnp_devices[] = {
 	/* ADS Cadet AM/FM Radio Card */
 	{.id = "MSM0c24", .driver_data = 0},
 	{.id = ""}

drivers/media/radio/radio-gemtek.c

@@ -281,7 +281,7 @@ static const struct radio_isa_ops gemtek_ops = {
 static const int gemtek_ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
 
 #ifdef CONFIG_PNP
-static struct pnp_device_id gemtek_pnp_devices[] = {
+static const struct pnp_device_id gemtek_pnp_devices[] = {
 	/* AOpen FX-3D/Pro Radio */
 	{.id = "ADS7183", .driver_data = 0},
 	{.id = ""}

drivers/media/radio/radio-sf16fmr2.c

@@ -197,7 +197,7 @@ static int fmr2_tea_ext_init(struct snd_tea575x *tea)
 	return 0;
 }
 
-static struct pnp_device_id fmr2_pnp_ids[] = {
+static const struct pnp_device_id fmr2_pnp_ids[] = {
 	{ .id = "MFRad13" }, /* tuner subdevice of SF16-FMD2 */
 	{ .id = "" }
 };