ARM: dts: stm32: enable CEC for stm32f769 discovery

enable cec for stm32f769 discovery board
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32f769-disco.dts

@@ -63,6 +63,12 @@ aliases {
 
 };
 
+&cec {
+	pinctrl-0 = <&cec_pins_a>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
 &clk_hse {
 	clock-frequency = <25000000>;
 };