usb/tusb6010: Convert sysbus init function to realize function

Use DeviceClass rather than SysBusDeviceClass in
tusb6010_class_init().

Cc: kraxel@redhat.com

Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Message-id: 20181130093852.20739-20-maozhongyi@cmss.chinamobile.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/usb/tusb6010.c

@@ -808,10 +808,10 @@ static void tusb6010_reset(DeviceState *dev)
     musb_reset(s->musb);
 }
 
-static int tusb6010_init(SysBusDevice *sbd)
+static void tusb6010_realize(DeviceState *dev, Error **errp)
 {
-    DeviceState *dev = DEVICE(sbd);
     TUSBState *s = TUSB(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 
     s->otg_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, tusb_otg_tick, s);
     s->pwr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, tusb_power_tick, s);
@@ -822,15 +822,13 @@ static int tusb6010_init(SysBusDevice *sbd)
     sysbus_init_irq(sbd, &s->irq);
     qdev_init_gpio_in(dev, tusb6010_irq, musb_irq_max + 1);
     s->musb = musb_init(dev, 1);
-    return 0;
 }
 
 static void tusb6010_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
-    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 
-    k->init = tusb6010_init;
+    dc->realize = tusb6010_realize;
     dc->reset = tusb6010_reset;
 }