ARM: socfpga: dts: Add support for terasic SoCkit

This adds basic support for the terasic SoCkit board.
The board includes an Altera Cyclone 5 SoC.

[Dinh Nguyen] - Changed to 115200 for baudrate in dts bootargs

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>