arm64: dts: exynos: drop unsupported UFS properties in ExynosAutov9 SADK

There is no vcc-fixed-regulator property for UFS nodes:

  exynosautov9-sadk.dtb: ufs@17e00000: Unevaluated properties are not allowed ('vcc-fixed-regulator' was unexpected)

Link: https://lore.kernel.org/r/20230120130108.278851-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>