Fix forcedeth hibernate/wake-on-lan problems

We currently don't signal the kernel we that this device can wake
the system.  Call device_init_wakeup() to correct this.
Without this device_can_wakeup and device_may_wakeup will return
incorrect values.
Together with the minimized acpi wakeup patch (6/4 ;)), which will
follow in the next mail, this really makes wake-on-lan work for me
as expected (i.e. "ethtool -s eth0 wol g" is sufficient, no
additional magic needed).

Signed-off-by: Tobias Diedrich <ranma+kernel@tdiedrich.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>