amd-xgbe: Reset running devices after resume from hibernate

After resume from hibernate on arm64, any amd-xgbe devices that were
running when we hibernated are reported as down, even when it is not.

Re-plugging the cables does not cause the interface to come back, the
link must be marked as down then up via 'ip set link' using the serial
console.

This happens because the device has been power-cycled and possibly
re-initialised by firmware, whereas the driver's memory structures have
been restored from the hibernate image and the two do not agree.

Schedule a restart of the device after powerup in case the world changed
while we were asleep.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>