cros_vm_lib: arc64 VMs support virtio-gpu

betty-arc64 and novato-arc64 support virtio-gpu so by default they
should use '-vga virtio' instead of '-vga cirrus'

BUG=b:62840059
TEST=cros_start_vm --board=betty-arc64 starts qemu with '-vga virtio'

Change-Id: Ia8100ec7f9a9ba9c31f37cc558a0c79fcf847e93
Reviewed-on: https://chromium-review.googlesource.com/695748
Commit-Ready: Nicolas Norvez <norvez@chromium.org>
Tested-by: Nicolas Norvez <norvez@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed