chore: import upstream snapshot with attribution

tools/train/source/models/MobilenetUtils.cpp

@@ -0,0 +1,33 @@
+//
+//  MobilenetUtils.cpp
+//  MNN
+//
+//  Created by MNN on 2020/01/10.
+//  Copyright © 2018, Alibaba Group Holding Limited
+//
+
+#include "MobilenetUtils.hpp"
+#include <algorithm>
+
+namespace MNN {
+namespace Train {
+namespace Model {
+
+// https://github.com/tensorflow/models/blob/master/research/slim/nets/mobilenet/mobilenet.py
+int makeDivisible(int v, int divisor, int minValue) {
+    if (minValue == 0) {
+        minValue = divisor;
+    }
+    int newV = std::max(minValue, int(v + divisor / 2) / divisor * divisor);
+
+    // Make sure that round down does not go down by more than 10%.
+    if (newV < 0.9 * v) {
+        newV += divisor;
+    }
+
+    return newV;
+}
+
+} // namespace Model
+} // namespace Train
+} // namespace MNN