drm/amd/display: Add symclk workaround during disable link output

[Why & How]
This is originally a change (9c75891f) in DCN32 because of the lack
of interface to set TX while keeping symclk on. Adding this workaround
to DCN314 will resolve the current issue.

Fixes: 9c75891f ("drm/amd/display: rework recent update PHY state commit")
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Leo Chen <sancchen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>