media: rcar-vin: Change link setup argument

The link setup callback once acted on each VIN instance, and expected to
be called once for each VIN instance. This have changed as the driver
grew support for later hardware generations and the callback is now
expected to setup links for all VIN in the group.

The argument to the callback has however remained a pointer to a single
VIN instance. This pointer was then used to get the group structure. Fix
this and pass the group as the single argument to the link setup
callback making the expectation of the function clear.

There is no intentional change in behavior.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20250613153434.2001800-4-niklas.soderlund+renesas@ragnatech.se


Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>