dt-bindings: qcom: qcom,gsbi: convert to dtschema

Convert the Qualcomm General Serial Bus Interface (GSBI) to DT
Schema.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220405063451.12011-10-krzysztof.kozlowski@linaro.org