[media] it913x: fix IT9135 AX sleep

Old IT9135 AX needs a little bit different register settings for
sleep than newer IT9135 BX. This has been broken always, as power
management of the whole driver, but it started to be problem as I
fixed clock. Earlier clock was disabled very first on sleep and
rest of the commands were skipped by the chip as no clock, leaving
tuner full power state. When I fixed clocks these PM bugs started
raising out as I/O errors.

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>