boot-qemu.py: Disable audio for m68k

A user might not have permission or environment to open an audio device,
resulting in:

  qemu-system-m68k: no default audio driver available

Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: nathanchance

boot-qemu.py

@@ -523,6 +523,7 @@ def __init__(self):
         self._default_kernel_path = Path('vmlinux')
         self._initrd_arch = self._qemu_arch = 'm68k'
         self._qemu_args += [
+            '-audio', 'none',
             '-cpu', 'm68040',
             '-M', 'q800',
             '-no-reboot',