USB: ftdi_sio: add vendor/product id for the Marvell SheevaPlug

For reference:
http://www.marvell.com/products/embedded_processors/developer/kirkwood/sheevaplug.jsp

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>