Pass ISA-specific O3 CPU as a constructor parameter instead of using setCPU functions.

Pass ISA-specific O3 CPU as a constructor parameter instead of using setCPU functions.

src/cpu/o3/alpha/cpu_impl.hh:
    Pass ISA-specific O3 CPU to FullO3CPU as a constructor parameter instead of using setCPU functions.

--HG--
extra : convert_revision : 74f4b1f5fb6f95a56081f367cce7ff44acb5688a