ASoC: dt-bindings: Add StarFive JH7110 PWM-DAC controller

Add bindings for the PWM-DAC controller on the JH7110
RISC-V SoC by StarFive Ltd.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Link: https://lore.kernel.org/r/20230814080618.10036-2-hal.feng@starfivetech.com


Signed-off-by: Mark Brown <broonie@kernel.org>