[media] af9035: fix dual tuner detection with PCTV 79e

The value 5 of the EEPROM_TS_MODE register (meaning dual tuner presence) is
only valid for AF9035 devices. For IT9135 devices it is invalid and led to a
false positive dual tuner mode detection with PCTV 79e.
Therefore on non-AF9035 devices and with value 5 the driver now defaults to
single tuner mode and outputs a regarding info message to log.

This fixes Bugzilla bug #118561.

Reported-by: Marc Duponcheel <marc@offline.be>
Signed-off-by: Stefan Pöschel <basic.master@gmx.de>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>