We don't do a proper job at freeing resources in cal_camerarx_create's
error paths.

Fix these, and also switch the phy allcation from kzalloc to
devm_kzalloc to simplify the code further.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>