arm64: dts: qcom: sc8180x: use generic ADC channel node names

arm64: dts: qcom: sc8180x: use generic ADC channel node names

ADC channel node names were changed to require generic 'channel'.  The
user-visible part is defined via label.

  sc8180x-lenovo-flex-5g.dtb: adc@3100: 'die-temp@6', 'ref-gnd@0', 'vref-1p25@1' do not match any of the regexes: '^channel@[0-9a-f]+$', 'pinctrl-[0-9]+'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230617171541.286957-10-krzysztof.kozlowski@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>