devlink: Add devlink reload action and limit options

devlink: Add devlink reload action and limit options

Add reload action and reload limit to devlink reload command to enable
the user to select the reload action required and constrains limits on
these actions that he may want to ensure.

The following reload actions are supported:
  driver_reinit: driver entities re-initialization, applying
                 devlink-param and devlink-resource values.
  fw_activate: firmware activate.

The uAPI is backward compatible, if the reload action option is omitted
from the reload command, the driver reinit action will be used.
Note that when required to do firmware activation some drivers may need
to reload the driver. On the other hand some drivers may need to reset
the firmware to reinitialize the driver entities. Therefore, the devlink
reload command returns the actions which were actually performed.

By default reload actions are not limited and driver implementation may
include reset or downtime as needed to perform the actions. However, if
reload limit is selected, the driver should perform only if it can do it
while keeping the limit constraints.

Reload limit added:
  no_reset: No reset allowed, no down time allowed, no link flap and no
            configuration is lost.

Command examples:
$devlink dev reload pci/0000:82:00.0 action driver_reinit
reload_actions_performed:
  driver_reinit

$devlink dev reload pci/0000:82:00.0 action fw_activate
reload_actions_performed:
  driver_reinit fw_activate

devlink dev reload pci/0000:82:00.1 action driver_reinit -jp
{
    "reload": {
        "reload_actions_performed": [ "driver_reinit" ]
    }
}

devlink dev reload pci/0000:82:00.0 action fw_activate -jp
{
    "reload": {
        "reload_actions_performed": [ "driver_reinit","fw_activate" ]
    }
}

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: David Ahern <dsahern@gmail.com>