rockchip: dts: rock64: Fix XHCI usage

If the VBUS regulator is always-on, XHCI will fail to detect USB 3.0
devices; USB 2.0 devices will work however.

Make the VBUS regulator controllable and tie it to only the XHCI. This
makes all three USB ports usable.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3328-rock64-u-boot.dtsi b/arch/arm/dts/rk3328-rock64-u-boot.dtsi
index e5946d2..8318bf4 100644
--- a/arch/arm/dts/rk3328-rock64-u-boot.dtsi
+++ b/arch/arm/dts/rk3328-rock64-u-boot.dtsi
@@ -12,5 +12,16 @@
 };
 
 &usb_host0_xhci {
+	vbus-supply = <&vcc_host_5v>;
 	status = "okay";
 };
+
+/*
+ * This makes XHCI responsible for toggling VBUS. This is needed to work
+ * around an issue where either XHCI only works with USB 2.0 or OTG doesn't
+ * work, depending on how VBUS is configured. Having USB 3.0 seems better.
+ */
+&vcc_host_5v {
+	/delete-property/ regulator-always-on;
+	/delete-property/ regulator-boot-on;
+};