[media] it913x: avoid division by zero on error case

Error on init leaves some internal divisor zero, which causes oops
later. Fix it by populating divisors even it fails.

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