[torch] Add torch cpp cpu target for torch/csrc/api/src files (#87327)
Summary: Duplicating fbcode target `fbcode//caffe2:torch-cpp-cpu` target in xplat. In D40460749 our user wants to use `torch::kNearest` enum which is defined in `torch/csrc/api/src/enum.cpp`. Adding this target to support it.
Test Plan: Rely on CI
Differential Revision: D40532087
Pull Request resolved: https://github.com/pytorch/pytorch/pull/87327
Approved by: https://github.com/ezyang
