media: af9013: wrap dvbv3 statistics via dvbv5

Driver has calculated dvbv5 statistics, so use those as a base for
legacy dvbv3 statistics. Wrap and convert needed values to dvbv3,
remove old dvbv3 statistic implementations.

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