ARM: imx6qdl-sabresd: set swbst_reg as vbus's parent reg

commit 40f73779 upstream.

USB vbus 5V is from PMIC SWBST, so set swbst_reg as vbus's
parent reg, it fixed a bug that the voltage of vbus is incorrect
due to swbst_reg is disabled after boots up.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

arch/arm/boot/dts/imx6qdl-sabresd.dtsi

@@ -35,6 +35,7 @@ reg_usb_otg_vbus: regulator@0 {
 			regulator-max-microvolt = <5000000>;
 			gpio = <&gpio3 22 0>;
 			enable-active-high;
+			vin-supply = <&swbst_reg>;
 		};
 
 		reg_usb_h1_vbus: regulator@1 {
@@ -45,6 +46,7 @@ reg_usb_h1_vbus: regulator@1 {
 			regulator-max-microvolt = <5000000>;
 			gpio = <&gpio1 29 0>;
 			enable-active-high;
+			vin-supply = <&swbst_reg>;
 		};
 
 		reg_audio: regulator@2 {