Extended the SF table to cover additioanl SF id range of external
controller.

A user optionallly provides the external controller number when user
wants to create SF on the external controller.

An example 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 external true splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>