i.MX6UL: icore: Add SPL_OF_CONTROL support

Add OF_CONTROL support for SPL code.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/arm/dts/imx6ul-isiot.dtsi b/arch/arm/dts/imx6ul-isiot.dtsi
index 9a3c35c..5007a88 100644
--- a/arch/arm/dts/imx6ul-isiot.dtsi
+++ b/arch/arm/dts/imx6ul-isiot.dtsi
@@ -82,6 +82,7 @@
 };
 
 &usdhc1 {
+	u-boot,dm-spl;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_usdhc1>;
 	cd-gpios = <&gpio1 19 GPIO_ACTIVE_LOW>;
@@ -128,6 +129,7 @@
 	};
 
 	pinctrl_usdhc1: usdhc1grp {
+		u-boot,dm-spl;
 		fsl,pins = <
 			MX6UL_PAD_SD1_CMD__USDHC1_CMD     0x17059
 			MX6UL_PAD_SD1_CLK__USDHC1_CLK     0x10059