[media] soc-camera: fix a recent multi-camera breakage on sh-mobile

With the introduction of CSI2 support on sh-mobile, the host driver
switched to using v4l2_device_call_until_err() with grp_id == 0 to
call subdev operations on the sensor and the CSI2 subdev. However,
this has broken multi-client set ups like the one on migor, because
that way all operations get called on both clients. To fix this add
a grp_id and set it to the client private context.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c
index 4628448..9219930 100644
--- a/drivers/media/video/soc_camera.c
+++ b/drivers/media/video/soc_camera.c
@@ -1071,6 +1071,9 @@
 		}
 	}
 
+	sd = soc_camera_to_subdev(icd);
+	sd->grp_id = (long)icd;
+
 	/* At this point client .probe() should have run already */
 	ret = soc_camera_init_user_formats(icd);
 	if (ret < 0)
@@ -1092,7 +1095,6 @@
 		goto evidstart;
 
 	/* Try to improve our guess of a reasonable window format */
-	sd = soc_camera_to_subdev(icd);
 	if (!v4l2_subdev_call(sd, video, g_mbus_fmt, &mf)) {
 		icd->user_width		= mf.width;
 		icd->user_height	= mf.height;