[media] media: coda: fix sizeimage setting in try_fmt

VIDIOC_TRY_FMT would incorrectly return bytesperline * height,
instead of width * height * 3 / 2.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>