scons: Move Transform and termcap functionality into their own files.

Change-Id: Ica08e93f3873a7eafd02fe7d44c3bdbf0ce7f6b7
Reviewed-on: https://gem5-review.googlesource.com/5565
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/SConscript

@@ -42,6 +42,8 @@ from os.path import basename, dirname, exists, isdir, isfile, join as joinpath
 
 import SCons
 
+from gem5_scons import Transform
+
 # This file defines how to build a particular configuration of gem5
 # based on variable settings in the 'env' build environment.