Wandboard quad was not ported into U-boot at the time of writing the README.

Add it to the list of Wandboard variants.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

Add support for the Quad version of Wandboard; fix compile warning resulting
from having 2G of memory.
Signed-off-by: Tapani Utriainen <tapani@technexion.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Stefano Babic <sbabic@denx.de>

Fix typo in wandboard README file.
Signed-off-by: Luka Perkov <luka@openwrt.org>

Wandboard is a development board that has two variants: one version based
on mx6 dual lite and another one based on mx6 solo.

For more details about Wandboard, please refer to: http://www.wandboard.org/Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>