[llvm-profdata] Accept --version argument

The `llvm-profdata --version` output now looks like:

  llvm-profdata
  LLVM (http://llvm.org/):
    LLVM version 17.0.0git
    Optimized build with assertions.

This makes llvm-profdata more consistent with other tools.

Reviewed By: simon_tatham

Differential Revision: https://reviews.llvm.org/D150964