scons: Get rid of a loop which touched all the param ptype attributes.

As far as I can tell, this code is left over from when gem5 used SWIG,
and is not necessary any more.

Change-Id: Id36887773d2fc1373ffe689ee1b50b4989bf5a38
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/49390
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>

src/SConscript

@@ -676,14 +676,6 @@ sys.meta_path.remove(importer)
 sim_objects = m5.SimObject.allClasses
 all_enums = m5.params.allEnums
 
-for name,obj in sorted(sim_objects.items()):
-    for param in obj._params.local.values():
-        # load the ptype attribute now because it depends on the
-        # current version of SimObject.allClasses, but when scons
-        # actually uses the value, all versions of
-        # SimObject.allClasses will have been loaded
-        param.ptype
-
 ########################################################################
 #
 # calculate extra dependencies