usb: gadget: replace usb_gadget::is_dualspeed with max_speed

This commit replaces usb_gadget's is_dualspeed field with
a max_speed field.

[ balbi@ti.com : Fixed DWC3 driver ]

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/net2280.c b/drivers/usb/gadget/net2280.c
index da2b9d0..9ee36fd 100644
--- a/drivers/usb/gadget/net2280.c
+++ b/drivers/usb/gadget/net2280.c
@@ -2698,7 +2698,7 @@
 	spin_lock_init (&dev->lock);
 	dev->pdev = pdev;
 	dev->gadget.ops = &net2280_ops;
-	dev->gadget.is_dualspeed = 1;
+	dev->gadget.max_speed = USB_SPEED_HIGH;
 
 	/* the "gadget" abstracts/virtualizes the controller */
 	dev_set_name(&dev->gadget.dev, "gadget");