net: sunhme: Just restart autonegotiation if we can't bring the link up

If we've tried regular autonegotiation and forcing the link mode, just
restart autonegotiation instead of reinitializing the whole NIC.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>