[media] smiapp: Input for PLL configuration is mostly static

The input values for PLL configuration are mostly static. So set them when
the sensor is registered.

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>