drm/msm/dp: Drop EV_USER_NOTIFICATION

drm/msm/dp: Drop EV_USER_NOTIFICATION

Currently, we queue an event for signalling HPD connect/disconnect. This
can mean a delay in plug/unplug handling and notifying DRM core when a
hotplug happens.

Drop EV_USER_NOTIFICATION and signal the IRQ event as part of hotplug
handling.

Signed-off-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Acked-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Tested-by: Val Packett <val@packett.cool> # x1e80100-dell-latitude-7455
Tested-by: Yongxing Mou <yongxing.mou@oss.qualcomm.com> # Hamoa IOT EVK, QCS8300 Ride
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/727607/
Link: https://lore.kernel.org/r/20260524-hpd-refactor-v6-5-cf3ab488dd7b@oss.qualcomm.com