ucc_geth: Do not bring the whole IF down when TX failure.

ucc_geth_close lacks a cancel_work_sync(&ugeth->timeout_work)
to stop any outstanding processing of TX fail. However, one
can not call cancel_work_sync without fixing the timeout function
otherwise it will deadlock. This patch brings ucc_geth in line with
gianfar:

Don't bring the interface down and up, just reinit controller HW
and PHY.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>