drm/amd/display: Only consider DISPCLK when using optimized boot path

[Description]
- Previous bug fix for audio issue included dtbclk and p-state
  on the optimized boot path which is incorarect
- We only care about DISPCLK in the optimized vs. non-optimized
  boot path to avoid audio issues

Reviewed-by: Saaem Rizvi <syedsaaem.rizvi@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>