drm/amd/display: [FW Promotion] Release 0.0.73

- Add reserved bits for future feature development
- Fix issue with mismatch with type const

Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>