net/core: Add support for getting VF GUIDs

net/core: Add support for getting VF GUIDs

Introduce a new ndo: ndo_get_vf_guid, to get from the net
device the port and node GUID.

New applications can choose to use this interface to show
GUIDs with iproute2 with commands such as:

- ip link show ib4
ib4: <BROADCAST,MULTICAST> mtu 4092 qdisc noop state DOWN mode DEFAULT group default qlen 256
link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
vf 0     link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff,
spoof checking off, NODE_GUID 22:44:33:00:33:11:00:33, PORT_GUID 10:21:33:12:00:11:22:10, link-state disable, trust off, query_rss off

Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>