All the DesignWare-based host drivers loop waiting for the link to come up,
but they do it several ways that are needlessly different.

Wait for the link to come up in a consistent style across all the
DesignWare drivers.  No functional change.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NPratyush Anand <pratyush.anand@gmail.com>