dt-bindings: iio: adc: qcom,spmi-vadc: fix PM8350 define

The defines from include/dt-bindings/iio/qcom,spmi-adc7-pm8350.h were
changed to take sid argument:

  Error: Documentation/devicetree/bindings/iio/adc/qcom,spmi-vadc.example.dts:99.28-29 syntax error

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221117121307.264550-1-krzysztof.kozlowski@linaro.org