ruby: Fix missing cxx_header in Switch

This patch addresses a warning related to the swig interface
generation for the Switch class. The cxx_header is now specified
correctly, and the header in question has got a few includes added to
make it all compile.
diff --git a/src/mem/ruby/network/simple/SimpleNetwork.py b/src/mem/ruby/network/simple/SimpleNetwork.py
index 217dc20..8d0442b 100644
--- a/src/mem/ruby/network/simple/SimpleNetwork.py
+++ b/src/mem/ruby/network/simple/SimpleNetwork.py
@@ -42,6 +42,6 @@
 
 class Switch(BasicRouter):
     type = 'Switch'
-    cxx_class = 'Switch'
+    cxx_header = 'mem/ruby/network/simple/Switch.hh'
     virt_nets = Param.Int(Parent.number_of_virtual_networks,
                           "number of virtual networks")
diff --git a/src/mem/ruby/network/simple/Switch.hh b/src/mem/ruby/network/simple/Switch.hh
index 05e90f2..2757e65 100644
--- a/src/mem/ruby/network/simple/Switch.hh
+++ b/src/mem/ruby/network/simple/Switch.hh
@@ -42,6 +42,8 @@
 #include <iostream>
 #include <vector>
 
+#include "mem/packet.hh"
+#include "mem/ruby/common/TypeDefines.hh"
 #include "mem/ruby/network/BasicRouter.hh"
 #include "params/Switch.hh"