uli526x: Add suspend and resume routines (updated)

Add suspend/resume support to the uli526x network driver (tested on x86_64,
with 'Ethernet controller: ALi Corporation M5263 Ethernet Controller, rev 40').

This patch is based on the suspend/resume code in the tg3 driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jeff@garzik.org>