[media] coda: delay coda_fill_bitstream()

coda_fill_bitstream() calls v4l2_m2m_buf_done() which is no longer allowed
before streaming was started.
Delay coda_fill_bitstream() until coda_start_streaming() and explicitly set
'start_streaming_called' before calling coda_fill_bitstream()

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>