net: netdevsim: Support setting dev->perm_addr on port creation

net: netdevsim: Support setting dev->perm_addr on port creation

Network management daemons that match on the device permanent address
currently have no virtual interface types to test against.
NetworkManager, in particular, has carried an out of tree patch to set
the permanent address on netdevsim devices to use in its CI for this
purpose.

To support this use case, support setting netdev->perm_addr when
creating a netdevsim port.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250710-netdevsim-perm_addr-v4-1-c9db2fecf3bf@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>