arm64: dta: qcom: sc7180: delete vdda-1p2 and vdda-0p9 from mdss_dp

Both vdda-1p2-supply and vdda-0p9-supply regulators are controlled
by dp combo phy. Therefore remove them from dp controller.

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1656690436-15221-1-git-send-email-quic_khsieh@quicinc.com