usb: usbtest: update bos test coverage to usb 2.1 device

The commit "usb: usbtest: support bos descriptor test for usb 3.0"
introduced a test for bos descriptor. And USB 2.1 device also can be
checked. So this patch extends the test coverage to support USB 2.1 device.
Reported-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NHuang Rui <ray.huang@amd.com>
Acked-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/usbtest.c

@@ -763,7 +763,7 @@ static int ch9_postconfig(struct usbtest_dev *dev)
 	 * there's always [9.4.3] a bos device descriptor [9.6.2] in USB
 	 * 3.0 spec
 	 */
-	if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0300) {
+	if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0210) {
 		struct usb_bos_descriptor *bos = NULL;
 		struct usb_dev_cap_header *header = NULL;
 		unsigned total, num, length;