[media] vb2: replace void *alloc_ctxs by struct device *alloc_devs

Make this a proper typed array. Drop the old allocate context code since
that is no longer used.

Note that the memops functions now get a struct device pointer instead of
the struct device ** that was there initially (actually a void pointer to
a struct containing only a struct device pointer).

This code is now a lot cleaner.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/rcar-vin/rcar-dma.c

@@ -974,7 +974,7 @@ static void return_all_buffers(struct rvin_dev *vin,
 
 static int rvin_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
 			    unsigned int *nplanes, unsigned int sizes[],
-			    void *alloc_ctxs[])
+			    struct device *alloc_devs[])
 
 {
 	struct rvin_dev *vin = vb2_get_drv_priv(vq);