media: ti-vpe: cal: handle cal_ctx_v4l2_register error

cal_async_notifier_complete() doesn't handle errors returned from
cal_ctx_v4l2_register(). Add the error handling.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>