videoenc: use GST_ROUND_UP_N() macro
videoenc: use GST_ROUND_UP_N() macro

Makes the code much easier to read and understand.

https://bugzilla.gnome.org/show_bug.cgi?id=781409

CapOM/gst-omx,varunkumara/test-repo,CapOM/gst-omx,varunkumara/test-repo,GStreamer/gst-omx,GStreamer/gst-omx,CapOM/gst-omx,varunkumara/test-repo,GStreamer/gst-omx