net/ixgbe: fix link up in FreeBSD

net/ixgbe: fix link up in FreeBSD

In FreeBSD environment, nic_uio drivers do not support interrupts,
rte_intr_callback_register() will fail to register interrupts.
We cannot make link status to change from down to up by interrupt
callback. So we need to wait for the controller to acquire link
when ports start. Through multiple tests, 5s should be enough.

Fixes: b9bd0f09fa15 ("ethdev: fix link status query")
Cc: stable@dpdk.org
Signed-off-by: Lunyuan Cui <lunyuanx.cui@intel.com>
Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>