mv3 small support det

ppocr/modeling/backbones/det_mobilenet_v3.py

@@ -32,6 +32,7 @@ class MobileNetV3():
         """
         self.scale = params['scale']
         model_name = params['model_name']
+        self.model_name = model_name
         self.inplanes = 16
         if model_name == "large":
             self.cfg = [
@@ -102,7 +103,8 @@ class MobileNetV3():
         inplanes = self.make_divisible(inplanes * scale)
         outs = []
         for layer_cfg in cfg:
-            if layer_cfg[5] == 2 and i > 2:
+            start_idx = 2 if self.model_name == 'large' else 0
+            if layer_cfg[5] == 2 and i > start_idx:
                 outs.append(conv)
             conv = self.residual_unit(
                 input=conv,