media: imx: imx7_mipi_csis: Power off the source when stopping streaming

The .s_stream() implementation incorrectly powers on the source when
stopping the stream. Power it off instead.

Fixes: 7807063b ("media: staging/imx7: add MIPI CSI-2 receiver subdev for i.MX7")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/imx/imx7-mipi-csis.c

@@ -577,7 +577,7 @@ static int mipi_csis_s_stream(struct v4l2_subdev *mipi_sd, int enable)
 		state->flags |= ST_STREAMING;
 	} else {
 		v4l2_subdev_call(state->src_sd, video, s_stream, 0);
-		ret = v4l2_subdev_call(state->src_sd, core, s_power, 1);
+		ret = v4l2_subdev_call(state->src_sd, core, s_power, 0);
 		mipi_csis_stop_stream(state);
 		state->flags &= ~ST_STREAMING;
 		if (state->debug)