[media] DocBook: fix media-ioc-device-info.xml type

The documentation had two media_version entries. The second one was a typo and
it should be driver_version instead. Correct this.

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