drm/amd/display: Revert "Disconnect non-DP with no EDID"

[Why]
Found a use case (IPKVM) that DP-VGA active dongle does
not return any EDID and the mentioned commit broke it.

[How]
This reverts "Disconnect non-DP with no EDID"

Signed-off-by: Roy Chan <roy.chan@amd.com>
Reviewed-by: Chris Park <Chris.Park@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>