drm/amd/display: Refactor VActive implementation

drm/amd/display: Refactor VActive implementation

[Why & How]
Refactors VActive accounting in PMO, and breaks down fill time
requirement by P-State type as it can result in drasitcally different
bandwidth requirements depending on the blackout length.

Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>