build_helper_configs.py: Add NS toolchain file arg

Add a NS toolchain file argument in NSPE build config.
Enables NSPE build to select Armclang/GNUARM toolchain.
Right now only support NSPE to use the same toolchain file as SPE build
does.

Change-Id: Ia6cd5ab57a14b29cda793a34805f0fc85d721b2f
Signed-off-by: David Hu <david.hu@arm.com>
2 files changed