uboot-imx

Don't wait for disconnected TSECs

The TSEC driver's PHY code waits a long time for autonegotiation to
complete, even if the link is down.  The PHY knows the link is
down or up before autonegotiation completes, so we can short-circuit
the process if the link is down.

Signed-off-by: Andy Fleming <afleming@freescale.com>