ARM: dts: imx6sl-evk: Fix display duplicate name warning

The lcdif node has a property named "display" and also a child node
called "display", which causes the following warning:

device-tree: Duplicate name in lcdif@02220000, renamed to "display#1"

Rename the child node name in order to avoid the warning.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/boot/dts/imx6sl-evk.dts

@@ -546,10 +546,10 @@ &lcdif {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_lcd>;
 	lcd-supply = <&reg_lcd_3v3>;
-	display = <&display>;
+	display = <&display0>;
 	status = "okay";
 
-	display: display {
+	display0: display0 {
 		bits-per-pixel = <32>;
 		bus-width = <24>;