[ETHTOOL]: let mortals use ethtool

There is no reason to not allow non-admin users to query network
statistics and settings.

[ Removed PHYS_ID and GREGS based upon feedback from Auke Kok
  and Michael Chan -DaveM]

Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>