qdev: fix hotplug when no -device is specified

The peripheral[-anon] containers are initialized lazily but since they sit on
sysbus, they can not be created after realize.  This was causing an abort() to
occur during hotplug if no -device option was used.

This was spotted by qemu-test::device-add.sh

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/qdev.c

@@ -1529,3 +1529,9 @@ void qdev_property_add_str(DeviceState *dev, const char *name,
                       qdev_property_release_str,
                       prop, errp);
 }
+
+void qdev_machine_init(void)
+{
+    qdev_get_peripheral_anon();
+    qdev_get_peripheral();
+}

hw/qdev.h

@@ -616,4 +616,12 @@ void qdev_property_add_str(DeviceState *dev, const char *name,
  */
 char *qdev_get_type(DeviceState *dev, Error **errp);
 
+/**
+ * @qdev_machine_init
+ *
+ * Initialize platform devices before machine init.  This is a hack until full
+ * support for composition is added.
+ */
+void qdev_machine_init(void);
+
 #endif

vl.c

@@ -3335,6 +3335,8 @@ int main(int argc, char **argv, char **envp)
     }
     qemu_add_globals();
 
+    qdev_machine_init();
+
     machine->init(ram_size, boot_devices,
                   kernel_filename, kernel_cmdline, initrd_filename, cpu_model);