drm/amd/display: DML21 Fixes

- Store state related info inside mode_lib.
- Fix bad DCFCLK deep sleep
- Update FAMS structure in DMUB header

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>