arch-arm,stdlib: ARM release for_kvm is moved to configs (#986)

This change sets the `release` of the ARM board at the config file
instead of overriding the release on the ArmBoard. This change partially
solves issue 932 as the system taking and restoring the checkpoint is
consistent across KVM and timing CPUs respectively.

Signed-off-by: Kaustav Goswami <kggoswami@ucdavis.edu>

src/python/gem5/components/boards/arm_board.py

@@ -113,13 +113,8 @@ class ArmBoard(ArmSystem, AbstractBoard, KernelDiskWorkload):
         requires(isa_required=ISA.ARM)
 
         # Setting up ARM release here. We use the ARM default release, which
-        # corresponds to an ARMv8 system. The default release is updated if
-        # the user is using any KVM cores.
+        # corresponds to an ARMv8 system.
         self.release = release
-        if any(core.is_kvm_core() for core in processor.get_cores()):
-            # KVM cores only work with VExpress_GEM5_V1()
-            if isinstance(platform, VExpress_GEM5_V1):
-                self.release = ArmDefaultRelease.for_kvm()
 
         # Setting multi_proc of ArmSystem by counting the number of processors.
         if processor.get_num_cores() == 1: