vl: recognize audiodev groups in configuration files

This is necessary for the q35 configuration tests to pass,
once audiodev becomes mandatory.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/docs/config/q35-emulated.cfg b/docs/config/q35-emulated.cfg
index c8806e6..b4bd7e8 100644
--- a/docs/config/q35-emulated.cfg
+++ b/docs/config/q35-emulated.cfg
@@ -288,3 +288,7 @@
   driver = "hda-duplex"
   bus = "ich9-hda-audio.0"
   cad = "0"
+  audiodev = "audiodev0"
+
+[audiodev "audiodev0"]
+  driver = "none"                      # CHANGE ME
diff --git a/docs/config/q35-virtio-graphical.cfg b/docs/config/q35-virtio-graphical.cfg
index 148b5d2..820860a 100644
--- a/docs/config/q35-virtio-graphical.cfg
+++ b/docs/config/q35-virtio-graphical.cfg
@@ -248,3 +248,7 @@
   driver = "hda-duplex"
   bus = "sound.0"
   cad = "0"
+  audiodev = "audiodev0"
+
+[audiodev "audiodev0"]
+  driver = "none"                      # CHANGE ME
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 3db4fd2..db04f98 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -2125,6 +2125,7 @@
 static bool is_qemuopts_group(const char *group)
 {
     if (g_str_equal(group, "object") ||
+        g_str_equal(group, "audiodev") ||
         g_str_equal(group, "machine") ||
         g_str_equal(group, "smp-opts") ||
         g_str_equal(group, "boot-opts")) {
@@ -2140,6 +2141,15 @@
         Visitor *v = qobject_input_visitor_new_keyval(QOBJECT(dict));
         object_option_add_visitor(v);
         visit_free(v);
+
+    } else if (g_str_equal(group, "audiodev")) {
+        Audiodev *dev = NULL;
+        Visitor *v = qobject_input_visitor_new_keyval(QOBJECT(dict));
+        if (visit_type_Audiodev(v, NULL, &dev, errp)) {
+            audio_define(dev);
+        }
+        visit_free(v);
+
     } else if (g_str_equal(group, "machine")) {
         /*
          * Cannot merge string-valued and type-safe dictionaries, so JSON