arch,cpu: Distribute KVM checks and get rid of ISA switch statement.

Because tags don't work properly on SimObject()s right now (which will
be fixed by my SCons series), there are extra checks which manually
exclude files that should be excluded by their tags automatically.

Change-Id: Idb110269d6400ae6892eac994e673121e49b937c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52495
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
6 files changed