config: skip access to branchPred in ARM KVM

Prevents runtime error:

AttributeError: object 'ArmV8KvmCPU' has no attribute 'branchPred'

Change-Id: Ic5765fd560381cbacc2fa2fd2e6f79d98433c535
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21299
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed