usb: add usb_otg20_descriptor for OTG 2.0 and above

OTG 2.0 introduces bcdOTG in otg descriptor to identify the OTG and EH
supplement release number with which the OTG device is compliant, this
patch adds structure usb_otg20_descriptor for OTG 2.0 and above.

Signed-off-by: Macpaul Lin <[e-mail]>
Signed-off-by: Li Jun <[e-mail]>
Reviewed-by: Roger Quadros <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

include/uapi/linux/usb/ch9.h

···
 	__u8  bmAttributes;	/* support for HNP, SRP, etc */
 } __attribute__ ((packed));
 
+/* USB_DT_OTG (from OTG 2.0 supplement) */
+struct usb_otg20_descriptor {
+	__u8  bLength;
+	__u8  bDescriptorType;
+
+	__u8  bmAttributes;	/* support for HNP, SRP and ADP, etc */
+	__le16 bcdOTG;		/* OTG and EH supplement release number
+				 * in binary-coded decimal(i.e. 2.0 is 0200H)
+				 */
+} __attribute__ ((packed));
+
 /* from usb_otg_descriptor.bmAttributes */
 #define USB_OTG_SRP		(1 << 0)
 #define USB_OTG_HNP		(1 << 1)	/* swap host/device roles */