em(4) update

["Sepherosa Ziehau" <sepherosa@xxxxxxxxx>]

Hi all,

following patch updates em(4) according to 6.0.5 em driver from Intel web site:
http://leaf.dragonflybsd.org/~sephe/em.diff

Tested on an 82540EM

Please test/review it.

If no problem or objection comes, I will commit two weeks later.

Best Regards,
sephe

--
Live Free or Die