In order to be able to configure all needed stuff on a port/netdevice
of a line card without the line card being present, introduce line card
provisioning. Basically by setting a type, provisioning process will
start and driver is supposed to create a placeholder for instances
(ports/netdevices) for a line card type.

Allow the user to query the supported line card types over line card
get command. Then implement two netlink command SET to allow user to
set/unset the card type.

On the driver API side, add provision/unprovision ops and supported
types array to be advertised. Upon provision op call, the driver should
take care of creating the instances for the particular line card type.
Introduce provision_set/clear() functions to be called by the driver
once the provisioning/unprovisioning is done on its side. These helpers
are not to be called directly due to the async nature of provisioning.

Example:
$ devlink port # No ports are listed
$ devlink lc
pci/0000:01:00.0:
  lc 1 state unprovisioned
    supported_types:
       16x100G
  lc 2 state unprovisioned
    supported_types:
       16x100G
  lc 3 state unprovisioned
    supported_types:
       16x100G
  lc 4 state unprovisioned
    supported_types:
       16x100G
  lc 5 state unprovisioned
    supported_types:
       16x100G
  lc 6 state unprovisioned
    supported_types:
       16x100G
  lc 7 state unprovisioned
    supported_types:
       16x100G
  lc 8 state unprovisioned
    supported_types:
       16x100G

$ devlink lc set pci/0000:01:00.0 lc 8 type 16x100G
$ devlink lc show pci/0000:01:00.0 lc 8
pci/0000:01:00.0:
  lc 8 state active type 16x100G
    supported_types:
       16x100G
$ devlink port
pci/0000:01:00.0/0: type notset flavour cpu port 0 splittable false
pci/0000:01:00.0/53: type eth netdev enp1s0nl8p1 flavour physical lc 8 port 1 splittable true lanes 4
pci/0000:01:00.0/54: type eth netdev enp1s0nl8p2 flavour physical lc 8 port 2 splittable true lanes 4
pci/0000:01:00.0/55: type eth netdev enp1s0nl8p3 flavour physical lc 8 port 3 splittable true lanes 4
pci/0000:01:00.0/56: type eth netdev enp1s0nl8p4 flavour physical lc 8 port 4 splittable true lanes 4
pci/0000:01:00.0/57: type eth netdev enp1s0nl8p5 flavour physical lc 8 port 5 splittable true lanes 4
pci/0000:01:00.0/58: type eth netdev enp1s0nl8p6 flavour physical lc 8 port 6 splittable true lanes 4
pci/0000:01:00.0/59: type eth netdev enp1s0nl8p7 flavour physical lc 8 port 7 splittable true lanes 4
pci/0000:01:00.0/60: type eth netdev enp1s0nl8p8 flavour physical lc 8 port 8 splittable true lanes 4
pci/0000:01:00.0/61: type eth netdev enp1s0nl8p9 flavour physical lc 8 port 9 splittable true lanes 4
pci/0000:01:00.0/62: type eth netdev enp1s0nl8p10 flavour physical lc 8 port 10 splittable true lanes 4
pci/0000:01:00.0/63: type eth netdev enp1s0nl8p11 flavour physical lc 8 port 11 splittable true lanes 4
pci/0000:01:00.0/64: type eth netdev enp1s0nl8p12 flavour physical lc 8 port 12 splittable true lanes 4
pci/0000:01:00.0/125: type eth netdev enp1s0nl8p13 flavour physical lc 8 port 13 splittable true lanes 4
pci/0000:01:00.0/126: type eth netdev enp1s0nl8p14 flavour physical lc 8 port 14 splittable true lanes 4
pci/0000:01:00.0/127: type eth netdev enp1s0nl8p15 flavour physical lc 8 port 15 splittable true lanes 4
pci/0000:01:00.0/128: type eth netdev enp1s0nl8p16 flavour physical lc 8 port 16 splittable true lanes 4

$ devlink lc set pci/0000:01:00.0 lc 8 notype
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>