[Pytorch, Sparsity] Integrate sparse qnnpack operator in framework
Summary:
Add QNNPACK specific packed params for sparse linear.
Add sparse linear dynamic op with appropriate registration.
Add python side LinearDynamic module for sparsity.
Add tests to validate sparse linear qnnpack kernels.
Note that since these test are mostly run on x86 platform and
given that 1x4 sparse kernels are implemented both in sse and arm,
LinearDynamic at the moment defaults to 1x4 pattern.
Plan is to add another diff that will allow a global override for 8x1 pattern
such that prepare/convert flow can work for exporting model for mobile.
Test Plan: buck run caffe2/torch/fb/model_optimization:sparsity_test
Reviewed By: z-a-f
Differential Revision: D26263480
fbshipit-source-id: 04ab60aec624d1ecce8cfb38b79c7e94f501cdf6