dpaa2-eth: Fix TX FQID values

Depending on when MC connects the DPNI to a MAC, Tx FQIDs may
not be available during probe time.

Read the FQIDs each time the link goes up to avoid using invalid
values. In case an error occurs or an invalid value is retrieved,
fall back to QDID-based enqueueing.

Fixes: 1fa0f68c

 ("dpaa2-eth: Use FQ-based DPIO enqueue API")
Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>