drm/amd/display: Disable DC Mode Capping On DCN321

Why:
Limiting clocks to DC mode max results in some
display modes to no longer be supported

How:
Disable the path that limits the clock values

Fixes: 3b718dca ("drm/amd/display: Filter out AC mode frequencies on DC mode systems")
Reviewed-by: Martin Leung <martin.leung@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Austin Zheng <austin.zheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>