ARM: dts: imx27-phytec-phycard-s-rdk: Add pinctrl definitions for SDHC2

This patch adds pinctrl definitions for SDHC2 for Phytec PCA100 RDK board.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>