media: renesas: vsp1: Store RPF partition configuration per RPF instance

The vsp1_partition structure stores the RPF partition configuration in a
single field for all RPF instances, while each RPF can have its own
configuration. Fix it by storing the configuration separately for each
RPF instance.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Fixes: ab45e858 ("media: v4l: vsp1: Allow entities to participate in the partition algorithm")
Reviewed-by: Jacopo Mondi <jacopo.mondi+renesas@ideasonboard.com>