netkvm: add 100 ms delay before link up on VF attach
netkvm: add 100 ms delay before link up on VF attach

On 2012r2/Win8.1 there is additional pause-restart after
the adapter is bound. So the adapter may complete first DHCP
packets with error if we try send them when the VF is paused.

Signed-off-by: Yuri Benditovich <9668326cb042de5d91fd7679dac7ca5ea402812c@daynix.com>

virtio-win/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows