drm/amd/display: Add dmub additional interface support for FAMS

[WHY&HOW]
Update dmub and driver interface for future FAMS revisions.

Reviewed-by: Anthony Koo <anthony.koo@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>