[media] af9035: enable AF9033 demod clock source for IT9135

Integrated RF tuner of IT9135 is connected to demod clock source
named dyn0_clk. Enable that clock source in order to provide stable
clock early enough.

Cc: Bimow Chen <Bimow.Chen@ite.com.tw>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>