drm/msm/dp: make dp_bridge_mode_valid() more precise

Make dp_connector_mode_valid() return precise MODE_CLOCK_HIGH rather
than generic MODE_BAD in case the mode clock is higher than
DP_MAX_PIXEL_CLK_KHZ (675 MHz).

Reviewed-by: Kuogee <Hsieh&lt;quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/489554/
Link: https://lore.kernel.org/r/20220615115920.6768-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>