This patch fixes the error
	drivers/usb/core/hub.c:3753: undefined reference to `usb_speed_string'
seen in various random configurations.

Cc: Sean Young <sean@mess.org>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>