xtensa: xtfpga: introduce SoC I/O bus

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/boot/dts/xtfpga-flash-16m.dtsi

 / {
-	flash: flash@f8000000 {
+	soc {
+		flash: flash@08000000 {
 			#address-cells = <1>;
 			#size-cells = <1>;
 			compatible = "cfi-flash";
-		reg = <0xf8000000 0x01000000>;
+			reg = <0x08000000 0x01000000>;
 			bank-width = <2>;
 			device-width = <2>;
 			partition@0x0 {
@@ -23,4 +24,5 @@ partition@0xfe0000 {
 				reg = <0x00fe0000 0x00020000>;
 			};
 		};
+	};
 };

arch/xtensa/boot/dts/xtfpga-flash-4m.dtsi

 / {
-	flash: flash@f8000000 {
+	soc {
+		flash: flash@08000000 {
 			#address-cells = <1>;
 			#size-cells = <1>;
 			compatible = "cfi-flash";
-		reg = <0xf8000000 0x00400000>;
+			reg = <0x08000000 0x00400000>;
 			bank-width = <2>;
 			device-width = <2>;
 			partition@0x0 {
@@ -15,4 +16,5 @@ partition@0x3f0000 {
 				reg = <0x003f0000 0x00010000>;
 			};
 		};
+	};
 };

arch/xtensa/boot/dts/xtfpga.dtsi

@@ -42,21 +42,28 @@ osc: main-oscillator {
 		};
 	};
 
-	serial0: serial@fd050020 {
+	soc {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "simple-bus";
+		ranges = <0x00000000 0xf0000000 0x10000000>;
+
+		serial0: serial@0d050020 {
 			device_type = "serial";
 			compatible = "ns16550a";
 			no-loopback-test;
-		reg = <0xfd050020 0x20>;
+			reg = <0x0d050020 0x20>;
 			reg-shift = <2>;
 			interrupts = <0 1>; /* external irq 0 */
 			clocks = <&osc>;
 		};
 
-	enet0: ethoc@fd030000 {
+		enet0: ethoc@0d030000 {
 			compatible = "opencores,ethoc";
-		reg = <0xfd030000 0x4000 0xfd800000 0x4000>;
+			reg = <0x0d030000 0x4000 0x0d800000 0x4000>;
 			interrupts = <1 1>; /* external irq 1 */
 			local-mac-address = [00 50 c2 13 6f 00];
 			clocks = <&osc>;
 		};
+	};
 };