Add TORCH_CUDA_API to FilterDescriptor (#35131)
Summary:
`FilterDescriptor` is missing a `TORCH_CUDA_API`, so this symbol is not exported from `torch_cuda.so`, and users could have trouble building cpp_extension when using cudnn.
cc: ptrblck
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35131
Differential Revision: D20604439
Pulled By: ezyang
fbshipit-source-id: c57414fc8a9df9cb1e910e2ec0a48cfdbe7d1779
