TS: Clean up

src/core/BufferAttribute.d.ts

@@ -1,6 +1,6 @@
-import {
-	Usage
-} from '../constants';
+import { Usage } from '../constants';
+import { Matrix3 } from './../math/Matrix3';
+import { Matrix4 } from './../math/Matrix4';
 
 /**
  * @see <a href="https://github.com/mrdoob/three.js/blob/master/src/core/BufferAttribute.js">src/core/BufferAttribute.js</a>