ARM: dts: imx27-phytec-phycore-rdk: Add DT node for camera module

This patch adds first I2C bus and PCA9536 device.
This device is used on Phytec PCM-970 RDK camera addon module.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>