Don't need to include sim/param.hh in sim_object.hh anymore.

Don't need to include sim/param.hh in sim_object.hh anymore.
Add explicit include of sim/param.hh to .cc files as needed.

cpu/base_cpu.cc:
cpu/exetrace.cc:
dev/etherint.cc:
sim/system.cc:
    Add include of sim/param.hh.
sim/sim_object.hh:
    Don't need to include sim/param.hh.

--HG--
extra : convert_revision : 8ed13f25c2087680230056ab7abb623e6a7699cf