configs: Add --kvm-userspace-gic to fs_bigLITTLE.py
configs: Add --kvm-userspace-gic to fs_bigLITTLE.py

This will allow a user to select gem5 simulation of the GIC via
command line; Necessary option when the simulated GIC != than the
host GIC

Signed-off-by: Giacomo Travaglini <8eef13a4f970e2e9372c8d26ad0737b760f99c02@arm.com>
Change-Id: I30e151b774ddfa7f4e91054a375254e15007af3f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/44006
Reviewed-by: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Reviewed-by: Richard Cooper <5451b9f082a6f419264dc2e8898d5200257ca9ce@arm.com>
Maintainer: Jason Lowe-Power <92de577f37050ad05b60626d2f17913f40dcb1a2@gmail.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5