devlink: Supporting add and delete of devlink port

devlink: Supporting add and delete of devlink port

Enable user to add and delete the devlink port.

Examples for adding and deleting one SF port:

Examples of add, show and delete commands:
$ devlink dev eswitch set pci/0000:06:00.0 mode switchdev

$ devlink port show
pci/0000:06:00.0/65535: type eth netdev ens2f0np0 flavour physical port 0 splittable false

Add devlink port of flavour 'pcipf' for PF number 0 SF number 88:

$ devlink port add pci/0000:06:00.0 flavour pcisf pfnum 0 sfnum 88
pci/0000:06:00.0/32768: type eth netdev eth6 flavour pcisf controller 0 pfnum 0 sfnum 88 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached

Delete newly added devlink port
$ devlink port del pci/0000:06:00.0/32768

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David Ahern <dsahern@kernel.org>