media: atomisp: Delay mapping sensors to inputs till atomisp_register_device_nodes()

Delay mapping sensors to inputs till atomisp_register_device_nodes()
time. There are 2 reasons for this:

1. This guarantees a stable input order independent of the sensor
   probe order.

2. This is a preparation patch for v4l2-async sensor probing support.

Link: https://lore.kernel.org/r/20230518153733.195306-7-hdegoede@redhat.com



Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>