ARM: tegra: Drop unit-address from parallel RGB output port

Fix the following W=1 build warning:
"Warning (unit_address_vs_reg): /host1x@50000000/dc@54200000/rgb/port@0:
 node has a unit name, but no reg or ranges property"

Signed-off-by: Maxim Schwalm <maxim.schwalm@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm/boot/dts/nvidia/tegra20-acer-a500-picasso.dts

@@ -65,7 +65,7 @@
 			rgb {
 				status = "okay";
 
-				port@0 {
+				port {
 					lcd_output: endpoint {
 						remote-endpoint = <&lvds_encoder_input>;
 						bus-width = <18>;

arch/arm/boot/dts/nvidia/tegra20-asus-tf101.dts

@@ -66,7 +66,7 @@
 			rgb {
 				status = "okay";
 
-				port@0 {
+				port {
 					lcd_output: endpoint {
 						remote-endpoint = <&lvds_encoder_input>;
 						bus-width = <18>;

arch/arm/boot/dts/nvidia/tegra30-asus-lvds-display.dtsi

@@ -10,7 +10,7 @@
 			rgb {
 				status = "okay";
 
-				port@0 {
+				port {
 					dpi_output: endpoint {
 						remote-endpoint = <&bridge_input>;
 						bus-width = <24>;

arch/arm/boot/dts/nvidia/tegra30-asus-tf700t.dts

@@ -15,7 +15,7 @@
 			rgb {
 				status = "okay";
 
-				port@0 {
+				port {
 					dpi_output: endpoint {
 						remote-endpoint = <&bridge_input>;
 						bus-width = <24>;