venc: reorganize stream/dynamic params
venc: reorganize stream/dynamic params

They are logically different and have different requirements:
 * stream params don't need the sn to be ready, and need to be done
   before the output buffers are sent to the DSP because they are
   appended to the buffers
 * dynamic params need the sn to be ready

Signed-off-by: Felipe Contreras <de77a8b9cd239b204c19c52ed62e48ab47243362@gmail.com>

community-ssu/gst-dsp,community-ssu/gst-dsp,community-ssu/gst-dsp,felipec/gst-dsp,felipec/gst-dsp