net/mlx4_core: Mask out host side virtualization features for guests

When VFs (guests in this context) issue the QUERY_DEV_CAP command, they
need not be told that host side virtualization features such as VST, FSM
(MAC anti-spoofing) and running > 80 VFs are supported by the device.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>