test: Default to linux qemu firmware

Direct kernel boot results in much faster boot times so let's use
it by default.

We disable it for tests that need to reboot because +-50% of the
time, doing a reboot when using direct kernel boot causes qemu to
hang on reboot. Until we figure that out, let's use UEFI for the
tests that need to reboot.

test/integration-test-wrapper.py

@@ -48,6 +48,7 @@ def main():
     parser.add_argument('--test-name', required=True)
     parser.add_argument('--test-number', required=True)
     parser.add_argument('--storage', required=True)
+    parser.add_argument('--firmware', required=True)
     parser.add_argument('mkosi_args', nargs="*")
     args = parser.parse_args()
 
@@ -119,6 +120,7 @@ def main():
         '--runtime-network=none',
         '--runtime-scratch=no',
         '--append',
+        '--qemu-firmware', args.firmware,
         '--kernel-command-line-extra',
         ' '.join([
             'systemd.hostname=H',