net: Update API for VF vlan protocol 802.1ad support

Introduce new rtnl UAPI that exposes a list of vlans per VF, giving
the ability for user-space application to specify it for the VF, as an
option to support 802.1ad.
We adjusted IP Link tool to support this option.

For future use cases, the new UAPI supports multiple vlans. For now we
limit the list size to a single vlan in kernel.
Add IFLA_VF_VLAN_LIST in addition to IFLA_VF_VLAN to keep backward
compatibility with older versions of IP Link tool.

Add a vlan protocol parameter to the ndo_set_vf_vlan callback.
We kept 802.1Q as the drivers' default vlan protocol.
Suitable ip link tool command examples:
  Set vf vlan protocol 802.1ad:
    ip link set eth0 vf 1 vlan 100 proto 802.1ad
  Set vf to VST (802.1Q) mode:
    ip link set eth0 vf 1 vlan 100 proto 802.1Q
  Or by omitting the new parameter
    ip link set eth0 vf 1 vlan 100

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>