unicore32-softmmu: Add puv3 dma support

This patch adds puv3 dma (Direct Memory Access) support,
include dma device simulation for kernel booting.

v1->v2: Add initialization to ret in puv3_dma_read.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/hw/puv3.c b/hw/puv3.c
index 3a14b27..9acfc5a 100644
--- a/hw/puv3.c
+++ b/hw/puv3.c
@@ -49,6 +49,7 @@
 
     /* Initialize minimal necessary devices for kernel booting */
     sysbus_create_simple("puv3_pm", PUV3_PM_BASE, NULL);
+    sysbus_create_simple("puv3_dma", PUV3_DMA_BASE, NULL);
     sysbus_create_simple("puv3_ost", PUV3_OST_BASE, irqs[PUV3_IRQS_OST0]);
     sysbus_create_varargs("puv3_gpio", PUV3_GPIO_BASE,
             irqs[PUV3_IRQS_GPIOLOW0], irqs[PUV3_IRQS_GPIOLOW1],