ehci-hub: 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/ehci-hub.c

@@ -688,7 +688,7 @@ ehci_hub_descriptor (
 	int		ports = HCS_N_PORTS (ehci->hcs_params);
 	u16		temp;
 
-	desc->bDescriptorType = 0x29;
+	desc->bDescriptorType = USB_DT_HUB;
 	desc->bPwrOn2PwrGood = 10;	/* ehci 1.0, 2.3.9 says 20ms max */
 	desc->bHubContrCurrent = 0;