If the HPD signal isn't hooked up to this panel we need a 200 ms
delay.  In the datasheet this is shown as the maximum time that HPD
will take to be asserted after power is given to the panel.
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20181025222134.174583-3-dianders@chromium.org