engicam: imx6: migrate to DM_SERIAL

Add the needed DT overrides and configs to enable UART in SPL.

Cc: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
diff --git a/arch/arm/dts/imx6qdl-icore-u-boot.dtsi b/arch/arm/dts/imx6qdl-icore-u-boot.dtsi
index f95d49d..12e46e3 100644
--- a/arch/arm/dts/imx6qdl-icore-u-boot.dtsi
+++ b/arch/arm/dts/imx6qdl-icore-u-boot.dtsi
@@ -5,6 +5,22 @@
 
 #include "imx6qdl-u-boot.dtsi"
 
+&soc {
+	u-boot,dm-pre-reloc;
+};
+
+&aips1 {
+	u-boot,dm-pre-reloc;
+};
+
+&pinctrl_uart4 {
+	u-boot,dm-pre-reloc;
+};
+
+&uart4 {
+	u-boot,dm-pre-reloc;
+};
+
 &usdhc1 {
 	u-boot,dm-spl;
 };