net/mlx5: E-Switch, Modify node guid on vf set MAC

In RoCE, the RDMA-CM needs the node guid to establish connection
between nodes.
Today, the node guid exposed to mlx5 Ethernet VFs is zero, therefore
RDMA-CM on the VF is broken.

Whenever the administrator sets a MAC for a VF, derive the node guid
from it and set it as well in the following way:
MAC: e4:1d:2d:b3:f4:01 -> node_guid: e4:1d:2d:ff:fe:b3:f4:01

Fixes: 77256579

 ('net/mlx5: E-Switch, Introduce Vport...')
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>