LU-11914 build: add a configure check for l_getsepol

LU-11914 build: add a configure check for l_getsepol

l_getsepol requires openssl-devel, so add a configure check for
openssl/evp.h header and EVP_MD_CTX_create function, and disable
building l_getsepol in case they are missing.

Lustre-change: https://review.whamcloud.com/34183
Lustre-commit: be6de3db9cace327b3d34870417c96c2ac705313

Test-Parameters: trivial
Change-Id: I31ddbc2f5300e9e38db9e00e2b7fbcac7f83d9e5
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Thomas Stibor <t.stibor@gsi.de>
Reviewed-on: https://review.whamcloud.com/34832
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>