dt-bindings: ufs: qcom: document SM6125 UFS

Document already upstreamed and used Qualcomm SM6125 UFS host controller to fix
dtbs_check warnings like:

  sm6125-xiaomi-laurel-sprout.dtb: ufs@4804000: compatible:0: 'qcom,sm6125-ufshc' is not one of ['qcom,msm8994-ufshc', ...
  sm6125-xiaomi-laurel-sprout.dtb: ufs@4804000: Unevaluated properties are not allowed ('compatible' was unexpected)

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Martin Botka <martin.botka@somainline.org>
Link: https://lore.kernel.org/r/20240326174632.209745-3-krzysztof.kozlowski@linaro.org


Signed-off-by: Rob Herring <robh@kernel.org>