[media] media/platform: convert drivers to use the new vb2_queue dev field

Stop using alloc_ctx and just fill in the device pointer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Fabien Dessenne <fabien.dessenne@st.com>
Acked-by: Benoit Parrot <bparrot@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>