dt-bindings: iio: adc: qcom: Add Qualcomm smb139x

Bindings for a charger controller chip found on sm8350

Signed-off-by: Nia Espera <nespera@igalia.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20231111-nia-sm8350-for-upstream-v4-1-3a638b02eea5@igalia.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>