ARM: dts: s5pv210: remove DMA controller bus node name to fix dtschema warnings

There is no need to keep DMA controller nodes under AMBA bus node.
Remove the "amba" node to fix dtschema warnings like:

  amba: $nodename:0: 'amba' does not match '^([a-z][a-z0-9\\-]+-bus|bus|soc|axi|ahb|apb)(@[0-9a-f]+)?$'
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Jonathan Bakker <xc-racer2@live.ca>
Link: https://lore.kernel.org/r/20200907161141.31034-6-krzk@kernel.org

arch/arm/boot/dts/s5pv210.dtsi

@@ -128,35 +128,28 @@ wakeup-interrupt-controller {
 			};
 		};
 
-		amba {
-			#address-cells = <1>;
-			#size-cells = <1>;
-			compatible = "simple-bus";
-			ranges;
-
-			pdma0: dma@e0900000 {
-				compatible = "arm,pl330", "arm,primecell";
-				reg = <0xe0900000 0x1000>;
-				interrupt-parent = <&vic0>;
-				interrupts = <19>;
-				clocks = <&clocks CLK_PDMA0>;
-				clock-names = "apb_pclk";
-				#dma-cells = <1>;
-				#dma-channels = <8>;
-				#dma-requests = <32>;
-			};
+		pdma0: dma@e0900000 {
+			compatible = "arm,pl330", "arm,primecell";
+			reg = <0xe0900000 0x1000>;
+			interrupt-parent = <&vic0>;
+			interrupts = <19>;
+			clocks = <&clocks CLK_PDMA0>;
+			clock-names = "apb_pclk";
+			#dma-cells = <1>;
+			#dma-channels = <8>;
+			#dma-requests = <32>;
+		};
 
-			pdma1: dma@e0a00000 {
-				compatible = "arm,pl330", "arm,primecell";
-				reg = <0xe0a00000 0x1000>;
-				interrupt-parent = <&vic0>;
-				interrupts = <20>;
-				clocks = <&clocks CLK_PDMA1>;
-				clock-names = "apb_pclk";
-				#dma-cells = <1>;
-				#dma-channels = <8>;
-				#dma-requests = <32>;
-			};
+		pdma1: dma@e0a00000 {
+			compatible = "arm,pl330", "arm,primecell";
+			reg = <0xe0a00000 0x1000>;
+			interrupt-parent = <&vic0>;
+			interrupts = <20>;
+			clocks = <&clocks CLK_PDMA1>;
+			clock-names = "apb_pclk";
+			#dma-cells = <1>;
+			#dma-channels = <8>;
+			#dma-requests = <32>;
 		};
 
 		adc: adc@e1700000 {