Separate CPU driver impl from reference driver.

Change-Id: Ifb484edda665959b81d7b1f890d108bfa20a535d
diff --git a/rsAllocation.h b/rsAllocation.h
index c6b918f..de79cba 100644
--- a/rsAllocation.h
+++ b/rsAllocation.h
@@ -70,9 +70,18 @@
         State state;
 
         struct DrvState {
-            mutable void * mallocPtrLOD0;
-            mutable uint32_t strideLOD0;
-        } drvState;
+            struct LodState {
+                void * mallocPtr;
+                size_t stride;
+                uint32_t dimX;
+                uint32_t dimY;
+                uint32_t dimZ;
+            } lod[android::renderscript::Allocation::MAX_LOD];
+            size_t faceOffset;
+            uint32_t lodCount;
+            uint32_t faceCount;
+        };
+        mutable DrvState drvState;
 
     };
     Hal mHal;