LU-9480 lnet: add Multi-Rail and Discovery ping feature bits

LU-9480 lnet: add Multi-Rail and Discovery ping feature bits

Claim ping features bit for Multi-Rail and Discovery.

Assert in lnet_ping_target_update() that no unknown bits will
be send over the wire.

Test-Parameters: trivial
Signed-off-by: Olaf Weber <olaf@sgi.com>
Change-Id: Ie84b155f1ae45e3c228a4e49dc898160b81efb94
Reviewed-on: https://review.whamcloud.com/25775
Reviewed-by: Olaf Weber <olaf.weber@hpe.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Amir Shehata <amir.shehata@intel.com>