When encoding to V210, make sure the CC side data makes it through
in the resulting AVPacket.  This is needed so the decklink output
module can put out captions when in 10-bit mode.

Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Marton Balint <cus@passwd.hu>