media: rcar-csi2: set default format if a unsupported one is requested

Instead of failing the set_fmt() if a unsupported format is requested
set a default one and return the changed format to the user.

Signed-off-by: Niklas Söderlund <[e-mail]>
Reported-by: Sakari Ailus <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/rcar-vin/rcar-csi2.c

···
 	struct v4l2_mbus_framefmt *framefmt;
 
 	if (!rcsi2_code_to_fmt(format->format.code))
-		return -EINVAL;
+		format->format.code = rcar_csi2_formats[0].code;
 
 	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
 		priv->mf = format->format;