[media] V4L: vb2: prepare to support multi-size buffers

In preparation for the forthcoming VIDIOC_CREATE_BUFS ioctl add a
"const struct v4l2_format *" argument to the .queue_setup() vb2
operation.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>