ASoC: dt-bindings: wlf,wm8994: Convert to dtschema

ASoC: dt-bindings: wlf,wm8994: Convert to dtschema

Convert the Wolfson WM1811/WM8994/WM8958 audio codecs bindings to DT
schema.

Changes against original binding:
1. Add missing LDO1VDD-supply and LDO2VDD-supply.
2. Use "gpios" suffix for wlf,ldo1ena and wlf,ldo2ena (Linux kernel's
   gpiolib already looks for both variants).
3. Do not require AVDD1-supply and DCVDD-supply, because at least on
   Arndale board with Exynos5250 these are being supplied by internal
   LDOs.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230322193541.827291-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>