KVM: selftests: access_tracking_perf_test: Add option to skip the sanity check

KVM: selftests: access_tracking_perf_test: Add option to skip the sanity check

Add an option to skip sanity check of number of still idle pages,
and set it by default to skip, in case hypervisor or NUMA balancing
is detected.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Co-developed-by: James Houghton <jthoughton@google.com>
Signed-off-by: James Houghton <jthoughton@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20250508184649.2576210-3-jthoughton@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>