systemc: Add the deprecated sc_module::end_module function.

The regression tests use this function. In the Accellera implementation
it seems to just do some error checking, so our version doesn't do
anything for now.

Change-Id: Icaad45e934bad69e301bc0234f73e69791940736
Reviewed-on: https://gem5-review.googlesource.com/10854
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/ext/core/sc_module.hh

@@ -141,6 +141,9 @@ class sc_module : public sc_object
     sc_module(const sc_module_name &);
     sc_module();
 
+    /* Deprecated, but used in the regression tests. */
+    void end_module() {}
+
     void reset_signal_is(const sc_in<bool> &, bool);
     void reset_signal_is(const sc_inout<bool> &, bool);
     void reset_signal_is(const sc_out<bool> &, bool);