net/mlx4_core: Set initial admin GUIDs for VFs

To have out of the box experience, the PF generates random GUIDs who
serve as the initial admin values.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>