Add minimal support for DevKit8000

These patches add board support for the Timll DevKit8000.

The DevKit8000 is a beagle board clone from Timll, sold by
armkits.com. The DevKit8000 has RS232 serial port, LCD, DVI-D,
S-Video, Ethernet, SD/MMC, keyboard, camera, SPI, I2C, USB and
JTAG interface.

Signed-off-by: Thomas Weber <weber@corscience.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>