tests: Run ALL unit-tests with the nightly script

The NULL run is missing ISA specific unit-tests

Change-Id: Ia468d2da0141c4834e932b63980ebe230912bfe2
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/64312
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

tests/nightly.sh

@@ -81,7 +81,7 @@ unit_test () {
     docker run -u $UID:$GID --volume "${gem5_root}":"${gem5_root}" -w \
         "${gem5_root}" --memory="${docker_mem_limit}" --rm \
         gcr.io/gem5-test/ubuntu-20.04_all-dependencies:latest \
-            scons build/NULL/unittests.${build} -j${compile_threads} \
+            scons build/ALL/unittests.${build} -j${compile_threads} \
             --ignore-style
 }