dpaa_eth: add four prioritised Tx traffic classes

Each traffic class corresponds to a WQ priority level. The number of Tx
netdev queues and frame queues is increased to NR_CPUS queues for each
traffic class. In addition, the priority of the Rx, Error and Conf queues
is lowered but their order is maintained.

By default, only one traffic class is enabled, only the low priority Tx
queues are used and only the corresponding netdev queues are advertised.

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>