If the PF driver does not support the new speed reporting capabilities
then use link_event instead of link_event_adv to get the speed.
Fixes: 48de41ca11f0 ("net/avf: enable link status update")
Cc: stable@dpdk.org
Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>