[media] af9033: wrap DVBv3 BER to DVBv5 BER

DVBv5 BER is calculated anyway, so just return it for legacy
read_ber() API too.

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