ARM: dts: STiH410: set DWC3 dual role mode to peripheral

On STi 96boards, configure by default the micro USB connector
(managed by DWC3 hardware block) in peripheral mode.
This will allow to use fastboot feature.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/dts/stih407-family.dtsi

@@ -655,7 +655,7 @@
 				compatible	= "snps,dwc3";
 				reg		= <0x09900000 0x100000>;
 				interrupts	= <GIC_SPI 155 IRQ_TYPE_NONE>;
-				dr_mode		= "host";
+				dr_mode		= "peripheral";
 				phy-names	= "usb2-phy", "usb3-phy";
 				phys		= <&usb2_picophy0>,
 						  <&phy_port2 PHY_TYPE_USB3>;