This patch changes the license to BSD-2 for all source files where the
copyright is held by Aeroflex Gaisler, Cobham Gaisler, or Gaisler Research.
Some files also includes copyright right statements from OAR and/or
embedded Brains in addition to Gaisler.
Updates #3053.
Move _CPU_Fatal_halt() declaration to <rtems/score/cpuimpl.h> and make sure it
is a proper declaration of a function which does not return. Fix the type of
the error code. If necessary, add the implementation to cpu.c. Implementing
_CPU_Fatal_halt() as a function makes it possible to wrap this function for
example to fully test _Terminate().
