ARM: dts: STiH410-B2260: clean unnecessary hdmi node overlay

sti-hdmi is already enabled in stih410.dtsi.
So no need to declare it here.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>

arch/arm/boot/dts/stih410-b2260.dts

@@ -174,12 +174,6 @@ hdmiddc: i2c@9541000 {
 			status = "okay";
 		};
 
-		sti-display-subsystem {
-			sti_hdmi: sti-hdmi@8d04000 {
-				status = "okay";
-			};
-		};
-
 		miphy28lp_phy: miphy28lp@9b22000 {
 
 			phy_port1: port@9b2a000 {