configs, tests: Use proper releases in KVM simulations

Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Change-Id: I071f3d9c4eb5e4c7df3052bb8db93fece30cd069
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/64073
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

configs/example/arm/fs_bigLITTLE.py

@@ -435,6 +435,7 @@ def build(options):
 
 def _build_kvm(options, system, cpus):
     system.kvm_vm = KvmVM()
+    system.release = ArmDefaultRelease.for_kvm()
 
     if options.kvm_userspace_gic:
         # We will use the simulated GIC.