usb: gadget: mv_udc: init next dtd ptr for dqh when init ep0

Set next dtd ptr to EP_QUEUE_HEAD_NEXT_TERMINATE for dqh when init ep0.
It means the dQH is empty.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c
index 80168d1..8dab8c4 100644
--- a/drivers/usb/gadget/mv_udc_core.c
+++ b/drivers/usb/gadget/mv_udc_core.c
@@ -96,6 +96,8 @@
 			(EP0_MAX_PKT_SIZE << EP_QUEUE_HEAD_MAX_PKT_LEN_POS)
 			| EP_QUEUE_HEAD_IOS;
 
+		ep->dqh->next_dtd_ptr = EP_QUEUE_HEAD_NEXT_TERMINATE;
+
 		epctrlx = readl(&udc->op_regs->epctrlx[0]);
 		if (i) {	/* TX */
 			epctrlx |= EPCTRL_TX_ENABLE