ixgbe: Add new ndo to trust VF

Implements the new netdev op to trust VF in ixgbe.

The administrator can turn on and off VF trusted by ip command which
supports trust message.
 # ip link set dev eth0 vf 1 trust on
or
 # ip link set dev eth0 vf 1 trust off

Send a ping to reset VF on changing the status of trusting.
VF driver will reconfigure its features on reset.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>