[media] V4L: sh-mobile-ceu-camera: prepare to support multi-size buffers

Prepare the sh_mobile_ceu_camera friver to support the new
VIDIOC_CREATE_BUFS and VIDIOC_PREPARE_BUF ioctl()s. The .queue_setup()
vb2 operation must be able to handle buffer sizes, provided by the
caller, and the .buf_prepare() operation must not use the currently
configured frame format for its operation.

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