ANDROID: kvm: arm64: add per_cpu/cpuX/trace file

The trace interface was present in android14-6.1 kernel, and is used by
perfetto (although perfetto can work without it), so we should keep it.

Bug: 428904926
Test: presubmit
Change-Id: I51cc82324b3ef1ad8a801ae54f427eaf8790acd2
Signed-off-by: Nikita Ioffe <ioffe@google.com>