V4L/DVB (13159): DocBook/frontend: use cross references for ioctls

Rename all sessions id's for frontend ioctls to match ioctl name and
add the proper cross-link references for those ioctls.

This also helps to identify what ioctls are missing specs.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>