xtensa: add support for KC705

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

arch/xtensa/boot/dts/kc705.dts

+/dts-v1/;
+/include/ "xtfpga.dtsi"
+/include/ "xtfpga-flash-128m.dtsi"
+
+/ {
+	compatible = "cdns,xtensa-kc705";
+	memory@0 {
+		device_type = "memory";
+		reg = <0x00000000 0x08000000>;
+	};
+};

arch/xtensa/boot/dts/xtfpga-flash-128m.dtsi

+/ {
+	soc {
+		flash: flash@00000000 {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			compatible = "cfi-flash";
+			reg = <0x00000000 0x08000000>;
+			bank-width = <2>;
+			device-width = <2>;
+			partition@0x0 {
+				label = "data";
+				reg = <0x00000000 0x06000000>;
+			};
+			partition@0x6000000 {
+				label = "boot loader area";
+				reg = <0x06000000 0x00800000>;
+			};
+			partition@0x6800000 {
+				label = "kernel image";
+				reg = <0x06800000 0x017e0000>;
+			};
+			partition@0x7fe0000 {
+				label = "boot environment";
+				reg = <0x07fe0000 0x00020000>;
+			};
+		};
+        };
+};