update to newer ixgbevf

[joaquincasares]

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html

[mlococo]

Not necessarily a blocker, but check to see if fixing this is quick.

[joaquincasares]

This used to be up to date with the kernel, but now we just need the following steps run in either pre_1, if manual confirmations need to be made, or in pre_2, if we can fully automate them: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html#enhanced-networking-ubuntu.

[mlococo]

Removing the 2.6-blocker tag from this. Building instance-stores is quite a bit more complicated than I realized and I'm running out of time to spend on this image-bake. Will investigate next time around.