Merge r283612:

Merge r283612:
  Add SIOCGI2C ioctl support to the driver. Would work only on ConnectX-3
  with fresh firmware. The low level code is based on code provided by
  Mellanox.

  Thanks to Mellanox and their distributor Must (http://mustcompany.ru)
  for providing hardware.

  In collaboration with:        Andre Melkoumian <andre mellanox.com>
  Reviewed by:          hselasky
  Sponsored by:         Netflix
  Sponsored by:         Nginx, Inc.

git-svn-id: svn://svn.freebsd.org/base/stable/10@286841 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f