systemc: Fix some paths in the tlm SCons(script|struct).

The code in util/systemc was moved into a subdirectory recently. The
scons support here referred to it, and needed to be updated.

Change-Id: Ib457d9bdafb2bba5058e6ecf99b9d33b3072c5b3
Reviewed-on: https://gem5-review.googlesource.com/c/13955
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
2 files changed