LU-9480 lnet: add LNET_PEER_CONFIGURED flag

LU-9480 lnet: add LNET_PEER_CONFIGURED flag

Add the LNET_PEER_CONFIGURED flag, which indicates that a peer
has been configured by DLC. This is used to enforce that only
DLC can modify such a peer.

This includes some further refactoring of the code that creates
or modifies peers to ensure that the flag is properly passed
through, set, and cleared.

Test-Parameters: trivial
Signed-off-by: Olaf Weber <olaf@sgi.com>
Change-Id: I647116ec19bc2f577732a02bf8efb52dad48a391
Reviewed-on: https://review.whamcloud.com/25783
Reviewed-by: Olaf Weber <olaf.weber@hpe.com>
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Amir Shehata <amir.shehata@intel.com>