media: radio-si470x: make si470x_viddev_template const

Make this const as it is only used in a copy operation in the files
referencing it. Add const to declaration in the header too.

Structure found using Coccienlle and changes done by hand.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/radio/si470x/radio-si470x-common.c

@@ -749,7 +749,7 @@ static const struct v4l2_ioctl_ops si470x_ioctl_ops = {
 /*
  * si470x_viddev_template - video device interface
  */
-struct video_device si470x_viddev_template = {
+const struct video_device si470x_viddev_template = {
 	.fops			= &si470x_fops,
 	.name			= DRIVER_NAME,
 	.release		= video_device_release_empty,

drivers/media/radio/si470x/radio-si470x.h

@@ -209,7 +209,7 @@ struct si470x_device {
 /**************************************************************************
  * Common Functions
  **************************************************************************/
-extern struct video_device si470x_viddev_template;
+extern const struct video_device si470x_viddev_template;
 extern const struct v4l2_ctrl_ops si470x_ctrl_ops;
 int si470x_get_register(struct si470x_device *radio, int regnr);
 int si470x_set_register(struct si470x_device *radio, int regnr);