drm/amd/display: Allow IPS2 during Replay

[Why & How]
Add regkey to block video playback in IPS2 by default

Allow idle optimizations in the same spot we allow Replay for
video playback usecases.

Avoid sending it when there's an external display connected by
modifying the allow idle checks to check for active non-eDP screens.

Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>