Configure ixgbe phy & gbic power

Setup phy and gbic power as per Linux 4.3.13 driver.

This fixes link not detected on X540-AT2 after booting to Linux which turns
the phy power off on detach.

Reviewed by: sbruno
MFC after: 2 days
Sponsored by: Multiplay
Differential Revision: https://reviews.freebsd.org/D5107