ARM: dts: Use peripheral mode for dwc3_1 on exynos5422-odroidxu3

DWC3 device found on Exynos SoCs cannot work in OTG mode alone, because
it lacks some OTG related control part. OTG mode operation is possible
only with external hardware logic (usually GPIO-based) specific to
the board. Right now, however, there is no driver for such logic and no
bindings, so the OTG mode is dysfunctional at all (this means that it
doesn't work as a peripheral nor as a host). This patch sets the operation
mode to peripheral to get DWC3_1 device at least somehow working. This can
be later updated, when proper OTG driver and bindings get developed.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

arch/arm/boot/dts/exynos5422-odroidxu3-lite.dts

@@ -67,5 +67,5 @@
 };
 
 &usbdrd_dwc3_1 {
-	dr_mode = "otg";
+	dr_mode = "peripheral";
 };

arch/arm/boot/dts/exynos5422-odroidxu3.dts

@@ -98,5 +98,5 @@
 };
 
 &usbdrd_dwc3_1 {
-	dr_mode = "otg";
+	dr_mode = "peripheral";
 };