[media] si2168: TS clock inversion control

TS clock polarity control implemented.

[Antti: Resolved simple conflict]

Signed-off-by: Evgeny Plehov <EvgenyPlehov@ukr.net>
Reviewed-by: Olli Salonen <olli.salonen@iki.fi>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>