LU-7734 lnet: configure peers from DLC

LU-7734 lnet: configure peers from DLC

This patch adds the ability to configure peers from the DLC
interface.

When a peer is added a primary NID should be provided. If none is
provided then the first NID in the list of NIDs will be used
as the primary NID.

Basic error checking is done at the DLC level to ensure properly
formatted NIDs. However, if a NID is a duplicate, this will be
detected when adding it in the kernel. Operation is halted, which
means some peer NIDs might have already been added, but not the
entire set. It's the role of the caller to backtrack and remove that
peer that failed to add.

When deleting a peer a primary NID or a normal NID can be provided.
If a standard NID is provided, then the peer is found, and the
primary NID is compared to the peer ni. If they are the same the
entire peer is deleted. Otherwise, only the identified peer ni is
deleted. If a set of NIDs are provided each one will be removed
from the peer identified by the peer NID in turn.

The existing show peer credits API can be used to show peer
information.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: Iaf588a062b44d74305aa9aa7d31c7341c6c384b9
Reviewed-on: http://review.whamcloud.com/18476
Tested-by: Jenkins
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Olaf Weber <olaf@sgi.com>