per channel quantization support (#24936)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24936
Per channel quantization support in qconv2d + tests
ghstack-source-id: 88897977
Test Plan:
buck test mode/dev caffe2/test:quantized -- --print-passing-details
```
Finished test run: https://our.intern.facebook.com/intern/testinfra/testrun/4222124656103386
Summary (total time 64.42s):
PASS: 33
FAIL: 0
SKIP: 3
caffe2/test:quantized - test_qlinear (test_quantized.TestDynamicQuantizedLinear)
caffe2/test:quantized - test_qnnpack_relu (test_quantized.TestQNNPackOps)
caffe2/test:quantized - test_qnnpack_linear (test_quantized.TestQNNPackOps)
FATAL: 0
TIMEOUT: 0
OMIT: 0
```
Differential Revision: D16909378
fbshipit-source-id: a5dbe00aab220a01557ef03c905dcbe4668432c4
