ARM: dts: vf610: use new GPIO support

Use GPIO support by adding SD card detection configuration and
GPIO pinmux for Colibri's standard GPIO pins. Attach the GPIO
pins to the iomuxc node to get the GPIO pin settings applied.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>