misc: check address range in the SystemC example

misc: check address range in the SystemC example

Using a wrong offset or memory size may lead to segmentation faults.
This patch adds an address range check and produces an error message.

Change-Id: I79a72c05879266daf61a83367fe4ae386d1958a4
Reviewed-on: https://gem5-review.googlesource.com/3482
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Matthias Jung <jungma@eit.uni-kl.de>