media: coda: fix decoder sequence init escape flag

coda_command_sync calls coda_command_async, which writes the
bit_stream_param context variable into the BIT_STREAM_PARAM register,
overwriting the previously set value during coda_start_decoding. Instead
of writing to the register, set bit_stream_param to ensure that the
decoder sequence init command is executed with the escape flag set.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>