drm/amd/display: Remove hardmax usage for dcn401

[WHY&HOW]
Hardmax message will be retired for dcn4, so this removes it.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>