Reorganize test dir to ensure test of installed pkg

tests/lib/cpuifs/passthrough/__init__.py

@@ -0,0 +1,11 @@
+from ..base import CpuifTestMode
+
+from peakrdl.regblock.cpuif.passthrough import PassthroughCpuif
+
+class Passthrough(CpuifTestMode):
+    cpuif_cls = PassthroughCpuif
+    rtl_files = []
+    tb_files = [
+        "passthrough_driver.sv",
+    ]
+    tb_template = "tb_inst.sv"