media: vimc: deb: fix default sink bayer format

The format of the sink pad should be a bayer mbus format.

This fixes a kernel NULL pointer dereference error that was caused when
the stream starts because the configured format was not found in the
pixelmap table.
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/vimc/vimc-debayer.c

@@ -66,7 +66,7 @@ struct vimc_deb_device {
 static const struct v4l2_mbus_framefmt sink_fmt_default = {
 	.width = 640,
 	.height = 480,
-	.code = MEDIA_BUS_FMT_RGB888_1X24,
+	.code = MEDIA_BUS_FMT_SRGGB8_1X8,
 	.field = V4L2_FIELD_NONE,
 	.colorspace = V4L2_COLORSPACE_DEFAULT,
 };