LU-2456 lnet: DLC Feature dynamic net config

LU-2456 lnet: DLC Feature dynamic net config

This is the third patch of a set of patches that enables DLC.

This patch adds the following features to LNET.  Currently these
features are not driven by user space.
- Adding/Deleting Networks dynamically
Two new functions were added:
 - lnet_dyn_add_ni()
    add an NI. if the NI is already added then fail with
    appropriate error code
 - lnet_dyn_del_ni()
    delete an existing NI.  If NI doesn't exist fail with
    appropriate failure code.
These functions shall be called from IOCTL.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Change-Id: I43c1c3303916b15772b19ea94f56fb277a9d87bb
Reviewed-on: http://review.whamcloud.com/9832
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Liang Zhen <liang.zhen@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>