media: rcar-vin: Handle parallel subdev in link_notify

Handle parallel subdevices in link_notify callback. If the notified link
involves a parallel subdevice, do not change routing of the VIN-CSI-2
devices and mark the VIN instance as using a parallel input. If the
CSI-2 link setup succeeds instead, mark the VIN instance as using CSI-2.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>