drm/amd/display: [FW Promotion] Release 0.0.89

- Add flag to control root clock gating in init_hw
- Add flag to indicate a diags environment is being used

Acked-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>