[media] tvp5150: fix tvp5150_fill_fmt()

The tvp5150 output video is interlaced so mark the format
field as alternate and reduce the height to the half.

[javier: split patch and write commit message]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>

drivers/media/i2c/tvp5150.c

@@ -852,10 +852,10 @@ static int tvp5150_fill_fmt(struct v4l2_subdev *sd,
 	tvp5150_reset(sd, 0);
 
 	f->width = decoder->rect.width;
-	f->height = decoder->rect.height;
+	f->height = decoder->rect.height / 2;
 
 	f->code = MEDIA_BUS_FMT_UYVY8_2X8;
-	f->field = V4L2_FIELD_SEQ_TB;
+	f->field = V4L2_FIELD_ALTERNATE;
 	f->colorspace = V4L2_COLORSPACE_SMPTE170M;
 
 	v4l2_dbg(1, debug, sd, "width = %d, height = %d\n", f->width,