[nnpack] create a new port

[luncliff]

What does your PR fix?

There was no port request for this project.

This is one of the 3rd party libraries for the PyTorch project. The PR will be used for future support of the libtorch port.

Which triplets are supported/not supported? Have you updated the CI baseline?

Looks like it supports Linux, Mac, iOS, and Android. The PR targets only 2 triplets.

• x64-osx
• x64-linux

The project doesn't have a configuration for Windows. (WIN32, AMD64, CMAKE_SYSTEM_NAME, etc.)

Does your PR follow the maintainer guide?

The library doesn't have a tag/release.

• PR Structure
  • Make separate Pull Requests per port. The PR requires [fp16] create a new port #16340 [pthreadpool] create a new port #16342
• Manifests and CONTROL files
  • vcpkg format-manifest
• Versioning
  • Follow common conventions for the "version" field
    ... we use the date that the commit was accessed by you, formatted as YYYY-MM-DD.

[luncliff]

The port will be rebased after the merge of #16340 #16342.

[JackBoosY]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[JackBoosY]

LGTM, already tested on Linux and OSX, curious why the CI status is N/A.