ARM: dts: imx6qdl-sabresd: Set LDO regulator supply

Setting the supply is optional but beneficial, it will cause PMIC
voltages to be dynamically changed with cpu frequency.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

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

@@ -548,6 +548,18 @@ &pwm1 {
 	status = "okay";
 };
 
+&reg_arm {
+       vin-supply = <&sw1a_reg>;
+};
+
+&reg_pu {
+       vin-supply = <&sw1c_reg>;
+};
+
+&reg_soc {
+       vin-supply = <&sw1c_reg>;
+};
+
 &snvs_poweroff {
 	status = "okay";
 };