tests/acceptance: Add a 'virt_kvm' test using the GICv3

tests/acceptance: Add a 'virt_kvm' test using the GICv3

The current 'virt_kvm' test is restricted to GICv2, but can also
work with a GICv3. Duplicate it but add a GICv3 test which can be
tested on some hardware.

Noticed while running:

 $ avocado --show=app run -t machine:virt tests/acceptance/
 ...
 (2/6) tests/acceptance/boot_linux.py:BootLinuxAarch64.test_virt_kvm: ERROR: Unexpected empty reply from server (1.82 s)

The job.log content is:

  L0351 DEBUG| Output: 'qemu-system-aarch64: host does not support in-kernel GICv2 emulation\n'

With this patch:

 $ avocado --show=app run -t device:gicv3 tests/acceptance/
 (1/1) tests/acceptance/boot_linux.py:BootLinuxAarch64.test_virt_kvm_gicv3: PASS (55.10 s)

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-Id: <20200929224857.1225107-1-philmd@redhat.com>