media: dvbdev.h: do some kernel-doc cleanups

Some kernel-doc warnings in <media/dvbdev.h> were introduced. A fixup
patch addressed them was already merged, but Randy's approach from:
https://lore.kernel.org/linux-media/20221203060931.19953-1-rdunlap@infradead.org

Had some advantages, as it moves the @dvbdev to the right place inside
dvb_remove_device() documentation and it makes clearer about what
refcounter struct dvb_device refers to.

So, apply the changes suggested by Randy.
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

include/media/dvbdev.h

@@ -130,7 +130,7 @@ struct dvb_adapter {
  * struct dvb_device - represents a DVB device node
  *
  * @list_head:	List head with all DVB devices
- * @ref:	reference counter
+ * @ref:	reference count for this device
  * @fops:	pointer to struct file_operations
  * @adapter:	pointer to the adapter that holds this device node
  * @type:	type of the device, as defined by &enum dvb_device_type.
@@ -266,10 +266,10 @@ int dvb_register_device(struct dvb_adapter *adap,
 /**
  * dvb_remove_device - Remove a registered DVB device
  *
+ * @dvbdev:	pointer to struct dvb_device
+ *
  * This does not free memory. dvb_free_device() will do that when
  * reference counter is empty
- *
- * @dvbdev:	pointer to struct dvb_device
  */
 void dvb_remove_device(struct dvb_device *dvbdev);