LU-10003 lnet: implement Netlink version of lnet distance API.

LU-10003 lnet: implement Netlink version of lnet distance API.

Userland can query the distance of a peer using an ioctl. Move
this over to Netlink so we can support large NIDs for IPv6
handling.

Test-Parameters: trivial testlist=sanity-lnet
Change-Id: I090538e4cc55fd26bd61888de659b99bba85a111
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53556
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>