Make memtest work with 8 memtesters

src/mem/physical.cc:
    Update comment to match memtest use
src/python/m5/objects/PhysicalMemory.py:
    Make memtester have a way to connect functionally
tests/configs/memtest.py:
    Properly create 8 memtesters and connect them to the memory system

--HG--
extra : convert_revision : e5a2dd9c8918d58051b553b5c6a14785d48b34ca

src/python/m5/objects/PhysicalMemory.py

@@ -5,6 +5,7 @@ from MemObject import *
 class PhysicalMemory(MemObject):
     type = 'PhysicalMemory'
     port = Port("the access port")
+    functional = Port("Functional Access Port")
     range = Param.AddrRange(AddrRange('128MB'), "Device Address")
     file = Param.String('', "memory mapped file")
     latency = Param.Latency(Parent.clock, "latency of an access")