omxvideodec: Don't interpolate timestamps
omxvideodec: Don't interpolate timestamps

We will get exactly one frame per input buffer and assigning
timestamps between frames if more than one OMX buffer is required
per frame easily confuses timestamp tracking in OMX.

GStreamer/gst-omx,freedesktop-unofficial-mirror/gstreamer__gst-omx,tjormola/gst-omx,changzhix/gst-omx,renesas-rcar/gst-omx,renesas-devel/gst-omx,ismelykh/gst-omx-deinterlace,surround-io/gst-omx,CapOM/gst-omx,ismelykh/gst-omx-deinterlace,leio/gst-omx,surround-io/gst-omx,01org/gst-omx,GStreamer/gst-omx,pliu6/gst-omx,changzhix/gst-omx,renesas-devel/gst-omx,pliu6/gst-omx,varunkumara/test-repo,RidgeRun/gst-omx,renesas-rcar/gst-omx,tjormola/gst-omx,CapOM/gst-omx,freedesktop-unofficial-mirror/gstreamer__gst-omx,varunkumara/test-repo,01org/gst-omx,varunkumara/test-repo,leio/gst-omx,xuguangxin/gst-omx,renesas-rcar/gst-omx,CapOM/gst-omx,RidgeRun/gst-omx,xuguangxin/gst-omx,GStreamer/gst-omx