atmel_lcdfb: Fix STN LCD support

Fixes STN LCD support for the atmel_lcdfb framebuffer driver.

This patch is the result of a work from Jan Altenberg and has
been tested on a Hitachi SP06Q002 on at91sam9261ek.

It adds a Kconfig switch that enables the proper LCD in the
board configuration file (STN or TFT). The switch is used
in arch/arm/mach-at91/at91sam9261_devices.c & board-sam9261ek.c
as an example.

This patch includes the "Fix wrong line_length calculation"
little one from Jan and Haavard (submitted earlier).

AT91 platform informations are directly submitted trough
the at91 maintainer, here :
http://article.gmane.org/gmane.linux.kernel/543158



Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Cc: "Antonino A. Daplas" <adaplas@gmail.com>
Cc: Jan Altenberg <jan.altenberg@linutronix.de>
Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>