dt-bindings: sound: sun4i-spdif: Add Allwinner H6 compatible

Allwinner H6 has a SPDIF controller with an increase of the fifo
size and a sligher difference in memory mapping compare to H3/A64.

This make it not compatible with the previous generation.

Introduce a specific bindings for H6 SoC.
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/allwinner,sun4i-a10-spdif.yaml

@@ -21,6 +21,7 @@ properties:
       - const: allwinner,sun4i-a10-spdif
       - const: allwinner,sun6i-a31-spdif
       - const: allwinner,sun8i-h3-spdif
+      - const: allwinner,sun50i-h6-spdif
       - items:
           - const: allwinner,sun8i-a83t-spdif
           - const: allwinner,sun8i-h3-spdif