drm/amd/display: Refactor for Replay Link off frame count

drm/amd/display: Refactor for Replay Link off frame count

[why]
To refine for link off frame count in diagnose tool,
the driver show the link off frame count number instead of showing link
off frame count level.

Reviewed-by: ChunTao Tso <chuntao.tso@amd.com>
Reviewed-by: Robin Chen <robin.chen@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Dennis Chan <dennis.chan@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>