V4L/DVB (6086): ivtv: fix output mode processing: UDMA_YUV wasn't cleared

- Always clear when stopping the decoder
- Clear if the filehandle that is being close was used for UDMA_YUV output.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>