virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit

virtio_net: Introduce VIRTIO_NET_F_STANDBY feature bit

This feature bit can be used by hypervisor to indicate virtio_net device to
act as a standby for another device with the same MAC address.

VIRTIO_NET_F_STANDBY is defined as bit 62 as it is a device feature bit.

Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 9805069d14c1b0b66b1600ea60cfc08f94841bd8)
Orabug: 28122104
Signed-off-by: Vijay Balakrishna <vijay.balakrishna@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
(cherry picked from commit c4b1cdd0459d953eddac306c3a1fc88c8d631e17)
Signed-off-by: Vijay Balakrishna <vijay.balakrishna@oracle.com>
Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Conflicts:
	drivers/net/virtio_net.c
(UEK4 doesn't have VIRTNET_FEATURES defined)
	include/uapi/linux/virtio_net.h
(there is an additional feature bitmap in UEK5 for virtio net which
cherry-pick inserted during merge)

Signed-off-by: Brian Maly <brian.maly@oracle.com>