can: kvaser_pciefd: Add devlink port support

can: kvaser_pciefd: Add devlink port support

Register each CAN channel of the device as an devlink physical port.
This makes it easier to get device information for a given network
interface (i.e. can2).

Example output:
  $ devlink dev
  pci/0000:07:00.0
  pci/0000:08:00.0
  pci/0000:09:00.0

  $ devlink port
  pci/0000:07:00.0/0: type eth netdev can0 flavour physical port 0 splittable false
  pci/0000:07:00.0/1: type eth netdev can1 flavour physical port 1 splittable false
  pci/0000:07:00.0/2: type eth netdev can2 flavour physical port 2 splittable false
  pci/0000:07:00.0/3: type eth netdev can3 flavour physical port 3 splittable false
  pci/0000:08:00.0/0: type eth netdev can4 flavour physical port 0 splittable false
  pci/0000:08:00.0/1: type eth netdev can5 flavour physical port 1 splittable false
  pci/0000:09:00.0/0: type eth netdev can6 flavour physical port 0 splittable false
  pci/0000:09:00.0/1: type eth netdev can7 flavour physical port 1 splittable false
  pci/0000:09:00.0/2: type eth netdev can8 flavour physical port 2 splittable false
  pci/0000:09:00.0/3: type eth netdev can9 flavour physical port 3 splittable false

  $ devlink port show can2
  pci/0000:07:00.0/2: type eth netdev can2 flavour physical port 2 splittable false

  $ devlink dev info
  pci/0000:07:00.0:
    driver kvaser_pciefd
    versions:
        running:
          fw 1.3.75
  pci/0000:08:00.0:
    driver kvaser_pciefd
    versions:
        running:
          fw 2.4.29
  pci/0000:09:00.0:
    driver kvaser_pciefd
    versions:
        running:
          fw 1.3.72

  $  sudo ethtool -i can2
  driver: kvaser_pciefd
  version: 6.8.0-40-generic
  firmware-version: 1.3.75
  expansion-rom-version:
  bus-info: 0000:07:00.0
  supports-statistics: no
  supports-test: no
  supports-eeprom-access: no
  supports-register-dump: no
  supports-priv-flags: no

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://patch.msgid.link/20250725123230.8-10-extja@kvaser.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>