media: ti-vpe: cal: Move all sensor-related init to .bound() notifier

The initialization of the context based on the connected sensor is split
between the async notifier .bound() and .complete() operations. Move it
all to a separate function and call it from .bound() operation to
prepare for the move of the notifiers from the contexts to the cal_dev.
Only V4L2 registration is kept in the .complete() operation.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>