devlink: Extend SF port attributes to have external attribute

devlink: Extend SF port attributes to have external attribute

Extended SF port attributes to have optional external flag similar to
PCI PF and VF port attributes.

External atttibute is required to generate unique phys_port_name when PF number
and SF number are overlapping between two controllers similar to SR-IOV
VFs.

When a SF is for external controller an example view of external SF
port and config sequence.

On eswitch system:
$ devlink dev eswitch set pci/0033:01:00.0 mode switchdev

$ devlink port show
pci/0033:01:00.0/196607: type eth netdev enP51p1s0f0np0 flavour physical port 0 splittable false
pci/0033:01:00.0/131072: type eth netdev eth0 flavour pcipf controller 1 pfnum 0 external true splittable false
  function:
    hw_addr 00:00:00:00:00:00

$ devlink port add pci/0033:01:00.0 flavour pcisf pfnum 0 sfnum 77 controller 1
pci/0033:01:00.0/163840: type eth netdev eth1 flavour pcisf controller 1 pfnum 0 sfnum 77 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached

phys_port_name construction:
$ cat /sys/class/net/eth1/phys_port_name
c1pf0sf77

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Vu Pham <vuhuong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>