Limit USB to High Speed

* There is an enumeration problem when using superspeed.
* This doesn't fix it with all hubs, but can enable fastboot to work on
some 3.0 hosts.

Change-Id: If4a603126b945bd8f84c3d6e975e1185530eb193
diff --git a/board/freescale/imx8mq_phanbell/imx8m_phanbell.c b/board/freescale/imx8mq_phanbell/imx8m_phanbell.c
index 0a89cf5..abdd88f 100644
--- a/board/freescale/imx8mq_phanbell/imx8m_phanbell.c
+++ b/board/freescale/imx8mq_phanbell/imx8m_phanbell.c
@@ -165,7 +165,7 @@
 #define USB_PHY_CTRL2_TXENABLEN0	BIT(8)
 
 static struct dwc3_device dwc3_device_data = {
-	.maximum_speed = USB_SPEED_SUPER,
+	.maximum_speed = USB_SPEED_HIGH,
 	.base = USB1_BASE_ADDR,
 	.dr_mode = USB_DR_MODE_PERIPHERAL,
 	.index = 0,