net/ixgbevf: fix link state

net/ixgbevf: fix link state

For ixgbevf kernel driver, link status changes from down to up
will trigger vf kernel driver send IXGBE_VF_RESET message to pf
kernel driver, after this, vf kernel driver will disable and enable
it self. By these series operations, the vf kernel driver report
link up. Besides, all these operations handles in kernel thread.
For DPDK user space driver, it only gets link status changes from
down to up, but miss IXGBE_VF_RESET message sending and reset itself.
If we will add fully implementation of link status change for DPDK
user space driver, we need take much more modification. We have
aligned that for link status changes from down to up we only notify
link is up, users need to reset vf port.

Fixes: dc66e5fd01b9 ("net/ixgbe: improve link state check on VF")
Cc: stable@dpdk.org
Signed-off-by: Rosen Xu <rosen.xu@intel.com>
Signed-off-by: Yanglong Wu <yanglong.wu@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>