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>