usb: mtu3: clear dual mode of u3port when disable device

If not clear u3port's dual mode when disable device, the IP
will fail to enter sleep mode when suspend.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1595834101-13094-10-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/mtu3/mtu3_core.c

@@ -131,8 +131,12 @@ static void mtu3_device_disable(struct mtu3 *mtu)
 	mtu3_setbits(ibase, SSUSB_U2_CTRL(0),
 		SSUSB_U2_PORT_DIS | SSUSB_U2_PORT_PDN);
 
-	if (mtu->ssusb->dr_mode == USB_DR_MODE_OTG)
+	if (mtu->ssusb->dr_mode == USB_DR_MODE_OTG) {
 		mtu3_clrbits(ibase, SSUSB_U2_CTRL(0), SSUSB_U2_PORT_OTG_SEL);
+		if (mtu->is_u3_ip)
+			mtu3_clrbits(ibase, SSUSB_U3_CTRL(0),
+				     SSUSB_U3_PORT_DUAL_MODE);
+	}
 
 	mtu3_setbits(ibase, U3D_SSUSB_IP_PW_CTRL2, SSUSB_IP_DEV_PDN);
 }