ARM: STi: DT: STiH407: Add a cec0 pin definition

This pin setup provides the correct configuration in order to
interact with the CEC HW.
Signed-off-by: Erwan Le Ray <erwan.leray@st.com>
Signed-off-by: Nicolas Vanhaelewyn <nicolas.vanhaelewyn@st.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>

arch/arm/boot/dts/stih407-pinctrl.dtsi

@@ -107,6 +107,14 @@ pio5: gpio@09615000 {
 				st,retime-pin-mask = <0x3f>;
 			};
 
+			cec0 {
+				pinctrl_cec0_default: cec0-default {
+					st,pins {
+						hdmi_cec = <&pio2 4 ALT1 BIDIR>;
+					};
+				};
+			};
+
 			rc {
 				pinctrl_ir: ir0 {
 					st,pins {