arm: dts: imx8mp: add of-list support to common imx8mp-u-boot.dtsi

Add support for OF-LIST to common imx8mp-u-boot.dtsi so that it can
be used with boards that have multiple DTB's.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP i.MX U-Boot Team <uboot-imx@nxp.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Teresa Remmet <t.remmet@phytec.de>
Cc: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>
diff --git a/arch/arm/dts/imx8mp-u-boot.dtsi b/arch/arm/dts/imx8mp-u-boot.dtsi
index cfc352a..20edd90 100644
--- a/arch/arm/dts/imx8mp-u-boot.dtsi
+++ b/arch/arm/dts/imx8mp-u-boot.dtsi
@@ -99,8 +99,9 @@
 
 		fit {
 			description = "Configuration to load ATF before U-Boot";
-			#address-cells = <1>;
 			fit,external-offset = <CONFIG_FIT_EXTERNAL_OFFSET>;
+			fit,fdt-list = "of-list";
+			#address-cells = <1>;
 
 			images {
 				uboot {
@@ -129,7 +130,7 @@
 					};
 				};
 
-				fdt {
+				@fdt-SEQ {
 					description = "NAME";
 					type = "flat_dt";
 					compression = "none";
@@ -141,13 +142,13 @@
 			};
 
 			configurations {
-				default = "conf";
+				default = "@config-DEFAULT-SEQ";
 
-				conf {
+				@config-SEQ {
 					description = "NAME";
+					fdt = "fdt-SEQ";
 					firmware = "uboot";
 					loadables = "atf";
-					fdt = "fdt";
 				};
 			};
 		};