configs,python: Clean some cruft out of m5.objects.

SimObject is already available as m5.SimObject, and it doesn't make a
lot of sense to expose m5.internal.params, part of the internals of
gem5's python interface, as a peer to all the SimObject types.

Change-Id: I3030c1eb261877fd9648c9d3d73b7dbbd4c24345
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/48364
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/common/ObjectList.py

@@ -35,6 +35,7 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import m5.objects
+import m5.internal.params
 import inspect
 import sys
 from textwrap import TextWrapper