sim: Remove some code for python versions less than 3.

We no longer support those versions of python.

Change-Id: I8f7312d8c252e4491525aa13c7d091467b96af6b
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49411
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>

src/sim/init.cc

@@ -189,11 +189,7 @@ EmbeddedPyBind::getMap()
     return objs;
 }
 
-#if PY_MAJOR_VERSION >= 3
 PyObject *
-#else
-void
-#endif
 EmbeddedPyBind::initAll()
 {
     std::list<EmbeddedPyBind *> pending;
@@ -228,9 +224,7 @@ EmbeddedPyBind::initAll()
         }
     }
 
-#if PY_MAJOR_VERSION >= 3
     return m_m5.ptr();
-#endif
 }
 
 void
@@ -266,7 +260,6 @@ m5Main(int argc, char **_argv)
 #endif
 
 
-#if PY_MAJOR_VERSION >= 3
     typedef std::unique_ptr<wchar_t[], decltype(&PyMem_RawFree)> WArgUPtr;
     std::vector<WArgUPtr> v_argv;
     std::vector<wchar_t *> vp_argv;
@@ -278,9 +271,6 @@ m5Main(int argc, char **_argv)
     }
 
     wchar_t **argv = vp_argv.data();
-#else
-    char **argv = _argv;
-#endif
 
     PySys_SetArgv(argc, argv);