coreos-kernel: enable ILO and assorted PHY drivers

- Support configuring HP iLO, user space should use a container.
- Many ethernet drivers also need a PHY driver but the associated PHY
  drivers are not enabled automatically. This change enables all the
  ones that appear to be related to ethernet drivers we already ship.
Merge pull request #977 from marineam/tg3

coreos-kernel: enable ILO and assorted PHY drivers