[media] af9033: remove all DVBv3 stat calculation logic

Statistics are now calculated for DVBv5 and those DVBv5 values are
returned for legacy DVBv3 calls also. So we could remove all old
statistics calculation logic.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>