PCI: altera: Check link status before retrain link

commit c622032ebc538cb3869c312ae3ad235a99da84b6 upstream.

Check the link status before retraining.  If the link is not up, don't
bother trying to retrain it.

[bhelgaas: split code move to separate patch, changelog]
Signed-off-by: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Claudius Heine <claudius.heine.ext@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>