[PULL][Trusty/Utopic] xgene-enet 10G & SGMII 1G support

[Dann Frazier]

These backports for the xgene-enet driver enable 10G support and SGMII
1G support, addressing the following issues:
  http://bugs.launchpad.net/bugs/1381084
  http://bugs.launchpad.net/bugs/1381216

Trusty
  git://kernel.ubuntu.com/dannf/trusty-xgene.git@xgene-enet-10GbE+SGMII
Utopic:
  git://kernel.ubuntu.com/dannf/ubuntu-utopic-hyperscale.git@xgene-enet-10GbE+SGMII