Use addrconf_addr_eui48() helper function to set the GUIDs and remove the
driver specific version.

Link: https://lore.kernel.org/r/20211031170743.81755-1-kamalheib1@gmail.comSigned-off-by: Kamal Heib <kamalheib1@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>