at91/picotux200: remove commenting usb device and dataflash support

as based on http://www.picotux.com/pt200/picotux200.pdf


these board does not have such I/O

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>