ARM: dts: Enable USB hub on Arndale

The Arndale has a SMSC USB3503 connected in hardware only mode like a PHY,
support it using the usb-nop-xceiv binding.

Note that due to a regrettable decision to use a regulator to represent
the reset signal this uses a fixed voltage regulator to do that, there
is a plan to use the reset controller binding once that is merged so it
does not seem worthwhile to fix the usb-nop-xceiv driver at this point.

Signed-off-by: Mark Brown <broonie@linaro.org>
Tested-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos5250-arndale.dts

@@ -541,4 +541,18 @@
 	rtc {
 		status = "okay";
 	};
+
+	usb_hub_bus {
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		// SMSC USB3503 connected in hardware only mode as a PHY
+		usb_hub: usb_hub {
+			compatible = "smsc,usb3503a";
+
+			reset-gpios = <&gpx3 5 1>;
+			connect-gpios = <&gpd1 7 1>;
+		};
+	};
 };