Disable first conv for inception v3 due to lacking of asym supporting for s8 conv case.

Author: guomingz

examples/tensorflow/image_recognition/inceptionv3.yaml

@@ -3,16 +3,20 @@ framework:
     inputs: input
     outputs: predict
 
-calibration:                                         
+calibration:
   - iterations: 5, 10
     algorithm:
         activation: minmax
 
 tuning:
-    metric:  
+    metric:
       - topk: 1
     accuracy_criterion:
       - relative: 0.01                              # the tuning target of accuracy loss percentage: 1%
     timeout: 0                                      # tuning timeout (seconds)
-    random_seed: 9527                               # random seed                       
-
+    random_seed: 9527                               # random seed
+    ops: {
+          'v0/cg/conv0/conv2d/Conv2D': {
+            'activation':  {'dtype': ['fp32']},
+          }
+        }