Add support for cpuif that have write strobes

tests/test_write_strobes/testcase.py

@@ -0,0 +1,9 @@
+from ..lib.sim_testcase import SimTestCase
+
+from ..lib.cpuifs.passthrough import Passthrough
+
+class Test(SimTestCase):
+    cpuif = Passthrough()
+
+    def test_dut(self):
+        self.run_test()