ARM: dts: imx27 phyCARD-S remove wrong I2C RTC

Fixup of commit "ARM: dts: Add device tree support for phycard pca100".

Remove wrong I2C RTC node.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>