remove support for HWC < 1.0

Change-Id: If7e676a6e3524afeb9af3875125d2131d95db38b
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 7bb3f81..857b82c 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -90,7 +90,7 @@
     status_t disable();
 
     // commits the list
-    status_t commit() const;
+    status_t commit();
 
     // release hardware resources and blank screen
     status_t release() const;