SurfaceFlinger: DispSync -> VsyncController

Refactor the old DispSync to separate between Vsync math (VsyncTracker)
and fence / vsync callback management (VsyncController)

Bug: 162888874
Test: examine systraces
Test: SF unit tests

Change-Id: Id275620380a21aeb0017e966910cbf24860cecef
33 files changed