mem: Add cache class destructor to avoid memory leaks

Make valgrind a little bit happier

src/mem/cache/cache_impl.hh

@@ -83,6 +83,16 @@ Cache<TagStore>::Cache(const Params *p)
         prefetcher->setCache(this);
 }
 
+template<class TagStore>
+Cache<TagStore>::~Cache()
+{
+    delete [] tempBlock->data;
+    delete tempBlock;
+
+    delete cpuSidePort;
+    delete memSidePort;
+}
+
 template<class TagStore>
 void
 Cache<TagStore>::regStats()