[media] coda: drop zero payload bitstream buffers

The buffers with zero payload are now dumped in coda_fill_bitstream and not
passed to coda_bitstream_queue. This avoids unnecessary fifo addition and
buffer sequence counter increment.

Signed-off-by: Zahari Doychev <zahari.doychev@linux.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>