[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>
diff --git a/drivers/media/pci/cobalt/cobalt-v4l2.c b/drivers/media/pci/cobalt/cobalt-v4l2.c
index 6c19cdfc..d05672f 100644
--- a/drivers/media/pci/cobalt/cobalt-v4l2.c
+++ b/drivers/media/pci/cobalt/cobalt-v4l2.c
@@ -45,7 +45,7 @@
 
 static int cobalt_queue_setup(struct vb2_queue *q,
 			unsigned int *num_buffers, unsigned int *num_planes,
-			unsigned int sizes[], void *alloc_ctxs[])
+			unsigned int sizes[], struct device *alloc_devs[])
 {
 	struct cobalt_stream *s = q->drv_priv;
 	unsigned size = s->stride * s->height;