USB: sisusbvga: Fix for USB 3.0

Super speed is also fast enough to let sisusbvga operate.
Therefor expand the checks.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>