fallout of cleaning-up libutils includes

Test: run & compile
Bug: n/a

Change-Id: I99e462d2db6560742fa3f065d5de50cd60111130
diff --git a/libs/gui/ConsumerBase.cpp b/libs/gui/ConsumerBase.cpp
index c26de66..8acdfed 100644
--- a/libs/gui/ConsumerBase.cpp
+++ b/libs/gui/ConsumerBase.cpp
@@ -27,6 +27,8 @@
 
 #include <hardware/hardware.h>
 
+#include <cutils/atomic.h>
+
 #include <gui/BufferItem.h>
 #include <gui/IGraphicBufferAlloc.h>
 #include <gui/ISurfaceComposer.h>