liquidio VF: indicate that disabling rx vlan offload is not allowed

NIC firmware does not support disabling rx vlan offload, but the VF driver
incorrectly indicates that it is supported.  The PF driver already does the
correct indication by clearing the NETIF_F_HW_VLAN_CTAG_RX bit in its
netdev->hw_features.  So just do the same thing in the VF.

Signed-off-by: Raghu Vatsavayi <raghu.vatsavayi@cavium.com>
Acked-by: Prasad Kanneganti <prasad.kanneganti@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>