Kernel RPC header installed

The build support is installing the kernel RPC header file rpc/auth.h. This clashes with the user land version of the same header file. Only install the user land version of the header file. The build output is:

....
rtems-libbsd-c88476d8c0def10bd3fcc0983c19f6d2536f65e1-x86_64-..../lib/include/rpc/auth.h (from freebsd/sys/rpc/auth.h)
....
rtems-libbsd-c88476d8c0def10bd3fcc0983c19f6d2536f65e1-x86_64-..../lib/include/rpc/auth.h (from freebsd/include/rpc/auth.h)
...

Noitice the same destination for the different files. This has been present for a long time and effects waf install if you have a lot of cores (edited output):

Build failed
Traceback (most recent call last):
  File "/opt/.../waflib/Build.py", line 598, in do_install
    self.copy_fun(src,tgt)
  File "/opt/.../waflib/Build.py", line 541, in copy_fun
    shutil.copy2(src,tgt)
  File "/usr/local/lib/python3.9/shutil.py", line 445, in copy2
    copystat(src, dst, follow_symlinks=follow_symlinks)
  File "/usr/local/lib/python3.9/shutil.py", line 384, in copystat
    lookup("utime")(dst, ns=(st.st_atime_ns, st.st_mtime_ns),
FileNotFoundError: [Errno 2] No such file or directory
....
waflib.Errors.WafError: Could not install the file '/opt/.../6/arm-rtems6/xilinx_zynq_microzed/lib/include/rpc/auth.h'