LU-7699 build: Convert lustre_ver.h.in into a static .h file

The AC_LUSTRE_{MAJOR,MINOR,PATCH,FIX} autoconf output values are
no longer necessary.  We can instead use AC_DEFINE to set the
LUSTRE_{MAJOR,MINOR,PATCH,FIX} CPP macros directly.  As a result,
the lustre_ver.h file no longer needs to be generated by autoconf
and it can be made into a static file.

At the same time we set LUSTRE_VERSION_STRING, even though it
is not strictly needed, to avoid additional divergence from
the client code in the upstream Linux kernel staging area.

Change-Id: I6b0364a7af1869beb6acedc63c034565af00ef06
Signed-off-by: Christopher J. Morrone <morrone2@llnl.gov>
Reviewed-on: http://review.whamcloud.com/18111


Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>