[media] cx231xx: don't use port 3 on the Conexant video grabber

It's not working reliably if port 3 is enabled.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/cx231xx/cx231xx-cards.c

@@ -263,6 +263,7 @@ struct cx231xx_board cx231xx_boards[] = {
 		.norm = V4L2_STD_PAL,
 		.no_alt_vanc = 1,
 		.external_av = 1,
+		.dont_use_port_3 = 1,
 		/* Actually, it has a 417, but it isn't working correctly.
 		 * So set to 0 for now until someone can manage to get this
 		 * to work reliably. */