LU-8560 libcfs: add autoconf test for crypto changes

LU-8560 libcfs: add autoconf test for crypto changes

For linux 4.5 kernels the simple ifdef test in
linux-crypto.c worked but with linux 4.6+ kernels
we need to add a proper crypto api test for the
new inline functions crypto_ahash_alg_name() and
crypto_ahash_driver_name().

Test-Parameters: trivial

Change-Id: Ic18808b622d374cf6dc2417220ed83adc43ea692
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: http://review.whamcloud.com/22205
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>