drm/amd/display: FreeSync LFC MIN/MAX update on current frame

- Update BTR/LFC logic so that V_TOTAL_MIN/MAX will take affect on current frame
- Add in FreeSync update to MPO code path

Signed-off-by: Eric Cook <Eric.Cook@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Anthony Koo <Anthony.Koo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>