libxsmm: 1.15 -> 1.16.1, improve derivation
libxsmm: 1.15 -> 1.16.1, improve derivation

The following changes are made to the derivation besides the version
bump:

- Move all buildInputs to nativeBuildInputs.
- Switch from Python 2 to Python 3.
- Build a dynamic library by default.
- Use gfortran version corresponding to gcc version.
- Enable parallel building.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs