qemu.tests: Add a new case for test multi queue for virtio scsi

A case for test multi queue for virtio scsi in new guests and hosts. It may failed with old version of guests.
cmd is incorrect, system_image use ide when run with --driveformat=virtio_scsi
    -drive id=drive_image1,if=none,cache=none,snapshot=off,aio=native,file=/root/autotest-devel/client/tests/virt/shared/data/images/rhel70-64-virtio.qcow2 \
    -device ide-hd,id=image1,drive=drive_image1,bus=ide.0,unit=0 \