libgralloc: Add support to use CAMERA_HEAP

- Adds flag GRALLOC_USAGE_PRIVATE_CAMERA_HEAP to use the dedicated
  CAMERA_HEAP
- Remove GRALLOC_USAGE_PRIVATE_CP_BUFFER which is not used anymore

Change-Id: Iefea88d9a67d2fa0ca74492f508e1d5508d08983
diff --git a/libgralloc/alloc_controller.cpp b/libgralloc/alloc_controller.cpp
index 677bb4e..6dbc42f 100644
--- a/libgralloc/alloc_controller.cpp
+++ b/libgralloc/alloc_controller.cpp
@@ -217,6 +217,9 @@
         }
     }
 
+    if(usage & GRALLOC_USAGE_PRIVATE_CAMERA_HEAP)
+        ionFlags |= ION_HEAP(ION_CAMERA_HEAP_ID);
+
     if(usage & GRALLOC_USAGE_PRIVATE_ADSP_HEAP)
         ionFlags |= ION_HEAP(ION_ADSP_HEAP_ID);