Use new HWC display type/count constants.

Change-Id: I774d0c68906ac6dc69268f708c30a6b0868b8816
diff --git a/services/surfaceflinger/DisplayDevice.h b/services/surfaceflinger/DisplayDevice.h
index 6f0ce88..8e24df7 100644
--- a/services/surfaceflinger/DisplayDevice.h
+++ b/services/surfaceflinger/DisplayDevice.h
@@ -38,6 +38,7 @@
 
 class DisplayInfo;
 class DisplaySurface;
+class IGraphicBufferProducer;
 class Layer;
 class SurfaceFlinger;
 class HWComposer;
@@ -56,8 +57,8 @@
         DISPLAY_ID_INVALID = -1,
         DISPLAY_PRIMARY     = HWC_DISPLAY_PRIMARY,
         DISPLAY_EXTERNAL    = HWC_DISPLAY_EXTERNAL,
-        NUM_DISPLAY_TYPES   = HWC_NUM_DISPLAY_TYPES,
-        DISPLAY_VIRTUAL     = HWC_NUM_DISPLAY_TYPES
+        DISPLAY_VIRTUAL     = HWC_DISPLAY_VIRTUAL,
+        NUM_BUILTIN_DISPLAY_TYPES = HWC_NUM_PHYSICAL_DISPLAY_TYPES,
     };
 
     enum {