sun4i-csi: drop read/write, enable VB2_DMABUF

For no obvious reason VB2_DMABUF was not enabled. Add this.

Also both read and write file ops were set, but this was not enabled
in the vb2 io_modes or in the device_caps capabilities. Drop this.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c

@@ -413,7 +413,7 @@ int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
 
 	q->min_buffers_needed = 3;
 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
-	q->io_modes = VB2_MMAP;
+	q->io_modes = VB2_MMAP | VB2_DMABUF;
 	q->lock = &csi->lock;
 	q->drv_priv = csi;
 	q->buf_struct_size = sizeof(struct sun4i_csi_buffer);

drivers/media/platform/sunxi/sun4i-csi/sun4i_v4l2.c

@@ -256,8 +256,6 @@ static const struct v4l2_file_operations sun4i_csi_fops = {
 	.open		= sun4i_csi_open,
 	.release	= sun4i_csi_release,
 	.unlocked_ioctl	= video_ioctl2,
-	.read		= vb2_fop_read,
-	.write		= vb2_fop_write,
 	.poll		= vb2_fop_poll,
 	.mmap		= vb2_fop_mmap,
 };