lcd: add support for Toppoly TDO24M series LCD panels

This type of LCD panel can be found on PXA3xx/Littleton platforms.
Add LCD device and SPI-based driver for this.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>