get rid of HAL pixelformats 5551 and 4444

Change-Id: I817510c3c7c0c3d95924c2ffc79e5727a6d6c48f
display: Export headers

Display headers used by other components should be at a common
location to avoid issues with future changes in paths.

Change-Id: Iaec21206b82dd7dae03e598b9ec46b3e6f1bbf71