ARM: dts: STiH407: Add label for sti-hdmi node

Needed to declare HDMI device in sound card
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>

arch/arm/boot/dts/stih407.dtsi

@@ -102,7 +102,7 @@ sti-tvout@8d08000 {
 							 <&clk_s_d2_quadfs 0>;
 			};
 
-			sti-hdmi@8d04000 {
+			sti_hdmi: sti-hdmi@8d04000 {
 				compatible = "st,stih407-hdmi";
 				reg = <0x8d04000 0x1000>;
 				reg-names = "hdmi-reg";