Clean fake sink flag after detecting link on downstream port.
Fixing display light-up after  "hot-unplug&plug again" downstream
of an active dongle.
Signed-off-by: NRoman Li <Roman.Li@amd.com>
Reviewed-by: NHarry Wentland <Harry.Wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>