Revert "drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes"

This reverts commit e467e0bd ("drm/msm/dp: use
drm_bridge_hpd_notify() to report HPD status changes").

The commit changed the way how the MSM DP driver communicates
HPD-related events to the userspace. The mentioned commit made some of
the HPD events being reported earlier. This way userspace starts poking
around. It interacts in a bad way with the dp_bridge_detect and the
driver's state machine, ending up either with the very long delays
during hotplug detection or even inability of the DP driver to report
the display as connected.

A proper fix will involve redesigning of the HPD handling in the MSM DP
driver. It is underway, but it will be intrusive and can not be thought
about as a simple fix for the issue. Thus, revert the offending commit.

Fixes: e467e0bd

 ("drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes")
Link: https://gitlab.freedesktop.org/drm/msm/-/issues/50
Reported-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/Zd3YPGmrprxv-N-O@hovoldconsulting.com/
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Paloma Arellano <quic_parellan@quicinc.com>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Patchwork: https://patchwork.freedesktop.org/patch/580313/
Link: https://lore.kernel.org/r/20240227220808.50146-1-dmitry.baryshkov@linaro.org