ARM: dts: socfpga: add i2c reset signals

Add the reset signals for the i2c controllers on Cyclone5-based
SoCFPGA boards to the dtsi.

Signed-off-by: Tim Sander <tim.sander@hbm.com>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>