drm/msm/hdmi: merge platform config for 8974/8084/8994/8996

Since there is no more difference between the HDMI platform data
between MSM8974/APQ8084/MSM8994/MSM8996, merge these configs into a
single entry.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/488868/
Link: https://lore.kernel.org/r/20220609122350.3157529-11-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>