displayconfig: Add tiled display config operations

The following tile display configuration operations are added:
- Query count of tiles on any display.
- Set the power state of a tile of a tiled display.
- Set the brightness level of a tile of a tiled display.
- Set Wider Async/Sync Mode preference on a tiled display.

Change-Id: I189e42f88323bb442063e6a9037be8aaaaa520a4
6 files changed