[media] cx23885: fix reversed I2C bus numbering

I2C buses for DVBSky T980C and S950C were numbered in an opposite
way compared to every other board in the driver. Switch numbering
to a more logical way.

Signed-off-by: Olli Salonen <olli.salonen@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>