ARM: dts: sti: Add stih410-b2260-u-boot.dtsi

STiH410 has 2 PHYs wired on the DWC3 IP, USB2 and USB3 PHYs.
As currently no U-boot driver is available for the USB3 PHY and to avoid
issue during DWC3 drive probe, we use DWC3 IP with only USB2 PHY
using stih410-b2260-u-boot.dtsi file.

Fixes: 2fd4242cc50e ("ubs: xhci-dwc3: Enable USB3 PHY when available")

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

arch/arm/dts/stih410-b2260-u-boot.dtsi

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
+ *
+ */
+
+/{
+	soc {
+		st_dwc3: dwc3@8f94000 {
+			dwc3: dwc3@9900000 {
+				phys = <&usb2_picophy0>;
+			};
+		};
+	};
+};