Rework cpuif to support transaction pipelining. Add more docs. update simulator

test/test_pipelined_cpuif/testcase.py

@@ -0,0 +1,9 @@
+from parameterized import parameterized_class
+
+from ..lib.regblock_testcase import RegblockTestCase
+from ..lib.test_params import TEST_PARAMS
+
+@parameterized_class(TEST_PARAMS)
+class Test(RegblockTestCase):
+    def test_dut(self):
+        self.run_test()