ARM: tegra: Enable HDMI CEC on Nyan

Enable HDMI CEC on Nyan Chromebooks. It allows to control TV over HDMI.
Suggested-by: Thomas Graichen <thomas.graichen@gmail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com> # T124 Nyan Big
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/tegra124-nyan.dtsi

@@ -390,6 +390,10 @@ pmc@7000e400 {
 		nvidia,sys-clock-req-active-high;
 	};
 
+	cec@70015000 {
+		status = "okay";
+	};
+
 	hda@70030000 {
 		status = "okay";
 	};