ARM: DT: STiH407: Add spdif_out pinctrl config

This patch adds the pinctrl config for the spidf out
pins used by the sasg codec IP.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Lee Jones <lee.jones@linaro.org>

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

@@ -1131,6 +1131,14 @@ st,pins {
 				};
 			};
 
+			spdif_out {
+				pinctrl_spdif_out: spdif_out{
+					st,pins {
+						spdif_out = <&pio34 7 ALT1 OUT>;
+					};
+				};
+			};
+
 			serial3 {
 				pinctrl_serial3: serial3-0 {
 					st,pins {