drm/msm/dp: Add "qcom, sc7280-dp" to support display port.

Changes in v2:
-- move "qcom,sc7280-dp" before "qcom,sc7280-edp"

Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/1638809846-31950-1-git-send-email-quic_khsieh@quicinc.com


Signed-off-by: Rob Clark <robdclark@chromium.org>