staging:lustre: move LNet NID macros to LNet layer

Currently several special macros LNet NID macros exist
in libcfs.h and libcfs_private.h. Move those macros
out to the lnet header types.h. The new lnet header
nidstr.h contains LNet NID string data that can be
used by user land LNet utilities and the LNet kernel
drivers.

Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>