net/mlx5e: Add tx reporter support

Add mlx5e tx reporter to devlink health reporters. This reporter will be
responsible for diagnosing, reporting and recovering of tx errors.
This patch declares the TX reporter operations and creates it using the
devlink health API. Currently, this reporter supports reporting and
recovering from send error CQE only. In addition, it adds diagnose
information for the open SQs.

For a local SQ recover (due to driver error report), in case of SQ recover
failure, the recover operation will be considered as a failure.
For a full tx recover, an attempt to close and open the channels will be
done. If this one passed successfully, it will be considered as a
successful recover.

The SQ recover from error CQE flow is not a new feature in the driver,
this patch re-organize the functions and adapt them for the devlink
health API. For this purpose, move code from en_main.c to a new file
named reporter_tx.c.

Diagnose output:
$devlink health diagnose pci/0000:00:09.0 reporter tx -j -p
{
    "SQs": [ {
            "sqn": 138,
            "HW state": 1,
            "stopped": false
        },{
            "sqn": 142,
            "HW state": 1,
            "stopped": false
        } ]
}

$devlink health diagnose pci/0000:00:09.0 reporter tx
SQs:
  sqn: 138 HW state: 1 stopped: false
  sqn: 142 HW state: 1 stopped: false

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Reviewed-by: Moshe Shemesh <moshe@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>