Make qemu-io commands available in HMP

It was decided to not make this command available in QMP in order to
make clear that this is not supposed to be a stable API and should be
used only for testing and debugging purposes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 4f5a3fd..396691a 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1553,6 +1553,22 @@
 ETEXI
 
     {
+        .name       = "qemu-io",
+        .args_type  = "device:B,command:s",
+        .params     = "[device] \"[command]\"",
+        .help       = "run a qemu-io command on a block device",
+        .mhandler.cmd = hmp_qemu_io,
+    },
+
+STEXI
+@item qemu-io @var{device} @var{command}
+@findex qemu-io
+
+Executes a qemu-io command on the given block device.
+
+ETEXI
+
+    {
         .name       = "info",
         .args_type  = "item:s?",
         .params     = "[subcommand]",