Fix some unset values in the request in the timing CPU.

Fix some unset values in the request in the timing CPU.
Properly implement the MSHR allocate function.

src/cpu/simple/timing.cc:
    Set the thread context in the CPU.

    Need to do this properly, currently I just set it to Cpu=0 Thread=0.  This will just cause all the stats in the cache based on these to just yield totals and not a distribution.
src/mem/cache/miss/mshr.cc:
    Properly implement the allocate function for the MSHR.

--HG--
extra : convert_revision : bcece518e54ed1404db3196f996a77b4dd5c1c1e