[media] cx231xx: Improve the media controller comment

There are two problems at the comment:
- it is badly idented;
- its comment doesn't mean anything.

Fix it.

Requested-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>