Fix memtester to use functional access, fix cache to work functionally now that we...

Fix memtester to use functional access, fix cache to work functionally now that we could test it.

src/cpu/memtest/memtest.cc:
    Fix memtest to do functional accesses
src/mem/cache/cache_impl.hh:
    Fix cache to handle functional accesses properly based on memtester changes
    Still need to fix functional accesses in timing mode now that the memtester can test it.

--HG--
extra : convert_revision : a6dbca4dc23763ca13560fbf5d41a23ddf021113