sdm: Add support for HDR

- Add LayerRequests to SDM Layer Interface, which will
  be used in informing any requests from SDM to client.
- Check for color metadata from client and handle
  HDR content.
- Include GPU Tonemapper to tonemap any requests
  coming from SDM

Change-Id: Idd1882ffab77fc3bff296114f36fb30bff4a4530
Crs-fixed: 1092142

sdm/include/utils/constants.h

@@ -71,6 +71,8 @@ namespace sdm {
   const int kMaxRotatePerLayer = 2;
   const uint32_t kMaxBlitTargetLayers = 2;
   const int kPageSize = 4096;
+  const uint32_t kGridSize = 129;  // size used for non-linear transformation before Tone-mapping
+  const uint32_t kLutDim = 17;  // Dim of the 3d LUT for tone-mapping.
 
   typedef void * Handle;