This patch adds I2C support for the SoCFPGA. Using the designware I2C
controller driver. It supports all 4 I2C busses on the SoCFPGA.

The designware I2C driver has now been converted to the
CONFIG_SYS_I2C framework. So lets enable it on SoCFPGA.

Tested on SoCrates.
Signed-off-by: NStefan Roese <sr@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Pavel Machek <pavel@denx.de>
Cc: Heiko Schocher <hs@denx.de>