media: zoran: from VB2_READ/WRITE: read/write isn't supported

The read/write file operations are not implemented, so no
need to set VB2_READ and VB2_WRITE flags.

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