ARM: dts: Add pinctrl support to exynos5410

Add the required pin configuration support to Exynos5410 using pinctrl
interface.

Signed-off-by: Hakjoo Kim <ruppi.kim@hardkernel.com>
[AF: Rebased, style changes]
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Pavel Fedin <p.fedin@samsung.com>
[k.kozlowski: Move pinctrl nodes into soc node]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>