[media] Documentation: DocBook: fix spelling mistake

Fix spelling mistake.

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
1 file changed