ethernet: wait for carrier before starting supplicant

After we set link parameters (auto-negotiation, speed, duplex) in
stage1, the carrier can go down for several seconds because the
Ethernet PHY needs to renegotiate the link. Wait that carrier goes up
before starting the supplicant or the EAPoL start packet can be lost
causing an authentication failure.

https://bugzilla.redhat.com/show_bug.cgi?id=1759797
18 jobs for bg/802-1x-wait-carrier-rh1765490 in 32 minutes and 17 seconds (queued for 38 seconds)
latest
Status Job ID Name Coverage
  Test
passed #914083
allowed to fail
checkpatch

00:01:04

manual #914089
allowed to fail manual
t_centos:7.5.1804
passed #914090
t_centos:7.6.1810

00:22:29

passed #914096
t_debian:10

00:22:51

passed #914095
t_debian:9

00:15:35

passed #914098
t_debian:sid

00:24:00

manual #914097
allowed to fail manual
t_debian:testing
manual #914084
allowed to fail manual
t_fedora:28
passed #914085
t_fedora:29

00:32:03

passed #914086
t_fedora:30

00:26:41

passed #914087
t_fedora:31

00:24:54

manual #914088
allowed to fail manual
t_fedora:rawhide
passed #914091
t_ubuntu:16.04

00:16:25

passed #914092
t_ubuntu:18.04

00:19:19

manual #914094
allowed to fail manual
t_ubuntu:devel
manual #914093
allowed to fail manual
t_ubuntu:rolling
 
  External
failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/861/

failed https://desktopqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/beaker-NetworkManager-gitlab-trigger-code-upstream/861/

05:04:58