LU-1461 libcfs: Fix crypto not to use x86 pcmul for non x86 arch

LU-1461 libcfs: Fix crypto not to use x86 pcmul for non x86 arch

Also fix x86 detection in configure.

This fixes a build failure on ppc64:

In file included from user-crypto.c:34:
/var/lib/jenkins/workspace/lustre-ppc-builder/arch/ppc64/
build_type/client/distro/el6/ib_stack/inkernel/BUILD/BUILD/
lustre-2.2.60/libcfs/include/libcfs/user-crypto.h:30:
error: 'regparm' attribute directive ignored

Signed-off-by: Oleg Drokin <green@whamcloud.com>
Change-Id: Icb229a9db0826420ecc431bc7f7f5e45ecbdbd37
Reviewed-on: http://review.whamcloud.com/3361
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>