media: mtk-cir: only allow protocols that have software decoders

RC_PROTO_BIT_ALL includes protocols like unknown and other that do not
have IR decoders by definition. If these protocols are set in the
allowed_protocols, they will show in the protocols sysfs file but cannot
be enabled.
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/rc/mtk-cir.c

@@ -340,7 +340,7 @@ static int mtk_ir_probe(struct platform_device *pdev)
 	ir->rc->map_name = map_name ?: RC_MAP_EMPTY;
 	ir->rc->dev.parent = dev;
 	ir->rc->driver_name = MTK_IR_DEV;
-	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL;
+	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 	ir->rc->rx_resolution = MTK_IR_SAMPLE;
 	ir->rc->timeout = MTK_MAX_SAMPLES * (MTK_IR_SAMPLE + 1);