Regardless of the requested queue count per traffic class, the enetc
driver allocates a number of TX rings equal to the number of TCs, and
hardcodes a queue configuration of "1@0 1@1 ... 1@max-tc". Other
configurations are silently ignored and treated the same.

Improve that by allowing what the user requests to be actually
fulfilled. This allows more than one TX ring per traffic class.
For example:

$ tc qdisc add dev eno0 root handle 1: mqprio num_tc 4 \
	map 0 0 1 1 2 2 3 3 queues 2@0 2@2 2@4 2@6
[  146.267648] fsl_enetc 0000:00:00.0 eno0: TX ring 0 prio 0
[  146.273451] fsl_enetc 0000:00:00.0 eno0: TX ring 1 prio 0
[  146.283280] fsl_enetc 0000:00:00.0 eno0: TX ring 2 prio 1
[  146.293987] fsl_enetc 0000:00:00.0 eno0: TX ring 3 prio 1
[  146.300467] fsl_enetc 0000:00:00.0 eno0: TX ring 4 prio 2
[  146.306866] fsl_enetc 0000:00:00.0 eno0: TX ring 5 prio 2
[  146.313261] fsl_enetc 0000:00:00.0 eno0: TX ring 6 prio 3
[  146.319622] fsl_enetc 0000:00:00.0 eno0: TX ring 7 prio 3
$ tc qdisc del dev eno0 root
[  178.238418] fsl_enetc 0000:00:00.0 eno0: TX ring 0 prio 0
[  178.244369] fsl_enetc 0000:00:00.0 eno0: TX ring 1 prio 0
[  178.251486] fsl_enetc 0000:00:00.0 eno0: TX ring 2 prio 0
[  178.258006] fsl_enetc 0000:00:00.0 eno0: TX ring 3 prio 0
[  178.265038] fsl_enetc 0000:00:00.0 eno0: TX ring 4 prio 0
[  178.271557] fsl_enetc 0000:00:00.0 eno0: TX ring 5 prio 0
[  178.277910] fsl_enetc 0000:00:00.0 eno0: TX ring 6 prio 0
[  178.284281] fsl_enetc 0000:00:00.0 eno0: TX ring 7 prio 0
$ tc qdisc add dev eno0 root handle 1: mqprio num_tc 8 \
	map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 1
[  186.113162] fsl_enetc 0000:00:00.0 eno0: TX ring 0 prio 0
[  186.118764] fsl_enetc 0000:00:00.0 eno0: TX ring 1 prio 1
[  186.124374] fsl_enetc 0000:00:00.0 eno0: TX ring 2 prio 2
[  186.130765] fsl_enetc 0000:00:00.0 eno0: TX ring 3 prio 3
[  186.136404] fsl_enetc 0000:00:00.0 eno0: TX ring 4 prio 4
[  186.142049] fsl_enetc 0000:00:00.0 eno0: TX ring 5 prio 5
[  186.147674] fsl_enetc 0000:00:00.0 eno0: TX ring 6 prio 6
[  186.153305] fsl_enetc 0000:00:00.0 eno0: TX ring 7 prio 7

The driver used to set TC_MQPRIO_HW_OFFLOAD_TCS, near which there is
this comment in the UAPI header:

        TC_MQPRIO_HW_OFFLOAD_TCS,       /* offload TCs, no queue counts */

which is what enetc was doing up until now (and no longer is; we offload
queue counts too), remove that assignment.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>