mem-ruby: Fix Prefetcher to RubyPrefetcher in StateMachine.

After renaming Prefetcher to RubyPrefetcher, the slicc generator
should be updated to correctly initialize the prefetcher with
the controller.

Change-Id: Ia12a4640c35aaedd70a4a14e5a10793b060ba924
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29974
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>

src/mem/slicc/symbols/StateMachine.py

@@ -87,7 +87,7 @@ class StateMachine(Symbol):
 
             self.symtab.registerSym(param.ident, var)
 
-            if str(param.type_ast.type) == "Prefetcher":
+            if str(param.type_ast.type) == "RubyPrefetcher":
                 self.prefetchers.append(var)
 
         self.states = OrderedDict()