[media] cx231xx: let is_tuner check the real i2c port and not the i2c master number

Get used i2c port from bus_nr and status of port_3 switch.

Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
1 file changed