V4L/DVB (13667): tw9910: modify output format

Correct tw9910 output format is Cb - Y - Cr - Y
which is defined in ITU-R BT.656.

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>