V4L/DVB (13717): [MB86A16] Statistics Updates

* Demodulator status check made reliable
* Code simplification for Viterbi Sync check, makes
  acquisition more reliable

* Implement a BER monitor
* Implement a Signal strength monitor
* Implement a "simple" UCB monitor, no real UCB monitor

Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>