Add preliminary support for RTL8168G, RTL8168GU and RTL8411B.
RTL8168GU has two variants(GMII and MII) but it uses the same chip
revision id.  Driver checks PCI device id of controller and
sets internal capability flag(i.e. jumbo frame and link speed down
in WOL).

H/W donated by:	RealTek Semiconductor Corp.
Add preliminary support for RTL8168EP.

Submitted by:	Edward O'Callaghan (eocallaghan <> alterapraxis dot com)