[media] smiapp-pll: Try other pre-pll divisors

The smiapp pll calculator assumed that the minimum pre-pll divisor was
perfect. That may not always be the case, so let's try the others, too.
Typically there are just a few alternatives.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>