arm64: dts: qcom: pmi8950: Fix VADC channel scaling factors

arm64: dts: qcom: pmi8950: Fix VADC channel scaling factors

Fix USBIN/DCIN scaling to match the downstream implementation [1].

Downstream defines the following scaling mappings [2], corresponding
to mainline pre-scaling values:

  <4>  ->  <1 20>
  <1>  ->  <1 3>

[1] https://github.com/LineageOS/android_kernel_qcom_msm8953/blob/e6b46fc6f52e754eef5ce6265c7d82a3622e0b0f/arch/arm64/boot/dts/qcom/pmi8950.dtsi#L55-L86
[2] https://github.com/LineageOS/android_kernel_qcom_msm8953/blob/e6b46fc6f52e754eef5ce6265c7d82a3622e0b0f/include/linux/qpnp/qpnp-adc.h#L342-L357

Signed-off-by: Antony Kurniawan Soemardi <linux@smankusors.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251004-fix-pmi8950-vadc-v1-2-3143ecab99e9@smankusors.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>