ASoC: sun4i-spdif: Add Allwinner H616 compatible

The SPDIF hardware block found in the H616 SoC has the same layout as
the one found in the H6 SoC, except that it is missing the receiver
side.

Add a new compatible string for it.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://msgid.link/r/20240127163247.384439-3-wens@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>