Update bus bridges now that snoop ranges are passed properly

Update bus bridges now that snoop ranges are passed properly

src/mem/bridge.cc:
    Update brdiges, now that snoop addresses are properly forwarded.
    Bus bridge should only handle snoops on the second phase (SNOOP_COMMIT)
src/mem/bus.cc:
src/mem/bus.hh:
    Make sure if a busBridge has access to both things that snoop and things that respond it only takes the request once

--HG--
extra : convert_revision : 26cc9ee4429be45d4476fa435e0e9a54843c2509