libs: encoder: h264: submit sps in case of IDR picture
libs: encoder: h264: submit sps in case of IDR picture

If the picture is IDR, also submit a SPS header.

This means when frame number reaches to keyframe-period or an force
key unit event arrives, we insert SPS/PPS again.

https://bugzilla.gnome.org/show_bug.cgi?id=776712

ceyusa/gstreamer-vaapi,ceyusa/gstreamer-vaapi,GStreamer/gstreamer-vaapi,GStreamer/gstreamer-vaapi