arm64: dts: qcom: sc7180: Fix ps8640 power sequence for Homestar rev4

When powering up the ps8640, we need to deassert PD right
after we turn on the vdd33 regulator. Unfortunately, the vdd33
regulator takes some time (~4ms) to turn on. Add in the delay
for the vdd33 regulator so that when the driver deasserts PD
that the regulator has had time to ramp.

Signed-off-by: yangcong <yangcong5@huaqin.corp-partner.google.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211115030155.9395-1-yangcong5@huaqin.corp-partner.google.com