arm64: dts: qcom: msm8996: Reduce vdd_apc voltage

Fixes: 5cdcdae2 (Merge remote-tracking branch
'msm8996-dt/tracking-qcomlt-msm8996-dt' into integration-linux-qcomlt)

During this merge, a conflict was not resolved correctly, and it ended
up reverting e40271f5 (arm64: dts: qcom: msm8996: Reduce vdd_apc
voltage). So let's reapply this change.

Reported-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>