selftests/bonding: re-add lladdr target test

selftests/bonding: re-add lladdr target test

It looks like this test has been accidentally dropped when resolving
conflicts in this Makefile.

Most probably because there were 3 different patches modifying this file
in parallel:

  commit 152e8ec77640 ("selftests/bonding: add a test for bonding lladdr target")
  commit bbb774d921e2 ("net: Add tests for bonding and team address list management")
  commit 2ffd57327ff1 ("selftests: bonding: cause oops in bond_rr_gen_slave_id")

The first one was applied in 'net-next' while the two other ones were
recently applied in the 'net' tree.

But that's alright, easy to fix by re-adding the missing one!

Fixes: 0140a7168f8b ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20220923082306.2468081-1-matthieu.baerts@tessares.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>