Add default attributes to fix conv benchmarks. (#295)
Add default attributes to fix conv benchmarks. (#295)

We're not able to run benchmarks if the default values are not added.
It's one of opdsl requrements.
iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox,iree-org/iree-llvm-sandbox