[media] au8522: be sure that the setup will happen at streamon time

The same demod is used on both analog and digital mode. We should
not let the commands for analog mode to happen while the device
is in digital mode. So, monitor it via streamon.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --cc drivers/media/dvb-frontends/au8522_decoder.c
Simple merge

diff --cc drivers/media/dvb-frontends/au8522_priv.h
Simple merge