enable test_link_down on t0 and t1 devices (#13582)

Approach
What is the motivation for this PR?
Fill the test gap.

How did you do it?
Change the test script

How did you verify/test it?
I tested it on T0, T1 and T2 DUTs in Microsoft's internal testbed and the new script works fine.

tests/platform_tests/test_link_down.py

@@ -19,7 +19,7 @@
 logger = logging.getLogger(__name__)
 
 pytestmark = [
-    pytest.mark.topology('t2'),
+    pytest.mark.topology('t0', 't1', 't2'),
     pytest.mark.disable_loganalyzer,
 ]