AT91SAM9261EK: hook up the ATMEL LCD driver

This patch makes the necessary adaptations (PIO configurations and
defines in config header file) to hook up the Atmel LCD driver to the
AT91SAM9261EK board.

Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>