r8a66597-hcd: use USB_DT_HUB

Fix  using the  bare number to set the 'bDescriptorType' field of the Hub
Descriptor while the value  is #define'd in <linux/usb/ch11.h>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/r8a66597-hcd.c

@@ -2136,7 +2136,7 @@ static int r8a66597_hub_status_data(struct usb_hcd *hcd, char *buf)
 static void r8a66597_hub_descriptor(struct r8a66597 *r8a66597,
 				    struct usb_hub_descriptor *desc)
 {
-	desc->bDescriptorType = 0x29;
+	desc->bDescriptorType = USB_DT_HUB;
 	desc->bHubContrCurrent = 0;
 	desc->bNbrPorts = r8a66597->max_root_hub;
 	desc->bDescLength = 9;