Better name usb braille device

Windows users need to know that they have to use the Baum driver to make
the qemu braille device work.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/usb/dev-serial.c

@@ -113,7 +113,7 @@ enum {
 static const USBDescStrings desc_strings = {
     [STR_MANUFACTURER]    = "QEMU",
     [STR_PRODUCT_SERIAL]  = "QEMU USB SERIAL",
-    [STR_PRODUCT_BRAILLE] = "QEMU USB BRAILLE",
+    [STR_PRODUCT_BRAILLE] = "QEMU USB BAUM BRAILLE",
     [STR_SERIALNUMBER]    = "1",
 };