usb: hcd: use USB_DT_*

Fix using the bare numbers to set the 'bDescriptorType' descriptor fields
while the values are #define'd in <linux/usb/ch9.h>.

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