refactor code for the packet, get rid of packet_impl.hh

and call it packet_access.hh and fix the #includes so
things compile right.

--HG--
extra : convert_revision : d3626c9715b9f7e51bb3ab8d97e971fad4e0b724

src/dev/uart8250.cc

@@ -42,6 +42,8 @@
 #include "dev/simconsole.hh"
 #include "dev/uart8250.hh"
 #include "dev/platform.hh"
+#include "mem/packet.hh"
+#include "mem/packet_access.hh"
 #include "sim/builder.hh"
 
 using namespace std;