ARM: dts: exynos: Add HDMI CEC pin definition to exynos4 pinctrl

Add pinctrl nodes for the HDMI CEC device to the Exynos4210 and
Exynos4x12 SoCs. These are required by the HDMI CEC device.

Signed-off-by: Kamil Debski <kamil@wypas.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>