media: davinci: make function arguments const

Make the function arguments of functions vpfe_{register/unregister}_ccdc_device
const as the pointer dev does not modify the fields of the structure
it points to. Also, declare the variable ccdc_dev const as it points to the
same structure as dev but it does not modify the fields as well.

Signed-off-by: Bhumika Goyal <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/davinci/ccdc_hw_device.h

···
 };
 
 /* Used by CCDC module to register & unregister with vpfe capture driver */
-int vpfe_register_ccdc_device(struct ccdc_hw_device *dev);
-void vpfe_unregister_ccdc_device(struct ccdc_hw_device *dev);
+int vpfe_register_ccdc_device(const struct ccdc_hw_device *dev);
+void vpfe_unregister_ccdc_device(const struct ccdc_hw_device *dev);
 
 #endif
 #endif

drivers/media/platform/davinci/vpfe_capture.c

···
 };
 
 /* ccdc device registered */
-static struct ccdc_hw_device *ccdc_dev;
+static const struct ccdc_hw_device *ccdc_dev;
 /* lock for accessing ccdc information */
 static DEFINE_MUTEX(ccdc_lock);
 /* ccdc configuration */
···
  * vpfe_register_ccdc_device. CCDC module calls this to
  * register with vpfe capture
  */
-int vpfe_register_ccdc_device(struct ccdc_hw_device *dev)
+int vpfe_register_ccdc_device(const struct ccdc_hw_device *dev)
 {
 	int ret = 0;
 	printk(KERN_NOTICE "vpfe_register_ccdc_device: %s\n", dev->name);
···
  * vpfe_unregister_ccdc_device. CCDC module calls this to
  * unregister with vpfe capture
  */
-void vpfe_unregister_ccdc_device(struct ccdc_hw_device *dev)
+void vpfe_unregister_ccdc_device(const struct ccdc_hw_device *dev)
 {
 	if (!dev) {
 		printk(KERN_ERR "invalid ccdc device ptr\n");