ASoC: rockchip: add bindings for spdif controller

this patch add compatible for rk3228/rk3328 spdif,
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/rockchip-spdif.txt

@@ -9,7 +9,9 @@ Required properties:
 - compatible: should be one of the following:
    - "rockchip,rk3066-spdif"
    - "rockchip,rk3188-spdif"
+   - "rockchip,rk3228-spdif"
    - "rockchip,rk3288-spdif"
+   - "rockchip,rk3328-spdif"
    - "rockchip,rk3366-spdif"
    - "rockchip,rk3368-spdif"
    - "rockchip,rk3399-spdif"

sound/soc/rockchip/rockchip_spdif.c

@@ -49,8 +49,12 @@ static const struct of_device_id rk_spdif_match[] = {
 	  .data = (void *)RK_SPDIF_RK3066 },
 	{ .compatible = "rockchip,rk3188-spdif",
 	  .data = (void *)RK_SPDIF_RK3188 },
+	{ .compatible = "rockchip,rk3228-spdif",
+	  .data = (void *)RK_SPDIF_RK3366 },
 	{ .compatible = "rockchip,rk3288-spdif",
 	  .data = (void *)RK_SPDIF_RK3288 },
+	{ .compatible = "rockchip,rk3328-spdif",
+	  .data = (void *)RK_SPDIF_RK3366 },
 	{ .compatible = "rockchip,rk3366-spdif",
 	  .data = (void *)RK_SPDIF_RK3366 },
 	{ .compatible = "rockchip,rk3368-spdif",