usb: add USB_OTG_ADP definition

Add USB_OTG_ADP definition for usb_otg_descriptor.bmAttributes.
Signed-off-by: Macpaul Lin <macpaul@gmail.com>
Signed-off-by: Li Jun <jun.li@freescale.com>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

include/uapi/linux/usb/ch9.h

@@ -688,6 +688,7 @@ struct usb_otg20_descriptor {
 /* from usb_otg_descriptor.bmAttributes */
 #define USB_OTG_SRP		(1 << 0)
 #define USB_OTG_HNP		(1 << 1)	/* swap host/device roles */
+#define USB_OTG_ADP		(1 << 2)	/* support ADP */
 
 /*-------------------------------------------------------------------------*/