ARM: imx6: DHCOM i.MX6 PDK: Fix usb-otg VBUS regulator

During the conversion of this board to DM_REGULATOR, usb-mass-storage
was broken and started failing with the following error:

        => ums 0 mmc 2
        UMS: LUN 0, dev 2, hwpart 0, sector 0x0, count 0xe90000
        Error enabling VBUS supply
        g_dnl_register: failed!, error: -38
        g_dnl_register failed

Fix this by adding the relevant GPIO to the regulator node.

Fixes: 4ca99fe81aea ("ARM: imx: dh-imx6: Enable DM regulator")
Signed-off-by: Harald Seiler <hws@denx.de>
diff --git a/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi b/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi
new file mode 100644
index 0000000..4c3b5e8
--- /dev/null
+++ b/arch/arm/dts/imx6qdl-dhcom-u-boot.dtsi
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: (GPL-2.0+)
+/*
+ * Copyright (C) 2020 Harald Seiler <hws@denx.de>
+ */
+
+&reg_usb_otg_vbus {
+	gpio = <&gpio3 31 GPIO_ACTIVE_HIGH>;
+	enable-active-high;
+};