p54usb: Comment out duplicate Medion MD40900 device id

The Medion MD40900 device id [0x0cde, 0x0006] is defined twice.
Comment out the duplicate.

Originally-by: Ben Collins <ben.collins@ubuntu.com>
Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>