arm: dts: imx8mm: sync dts from Linux Kernel

Sync dts for i.MX8MM from Linux Kernel 5.4.0-rc1

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/dts/imx8mm-evk-u-boot.dtsi b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
index 10d9a20..16093f2 100644
--- a/arch/arm/dts/imx8mm-evk-u-boot.dtsi
+++ b/arch/arm/dts/imx8mm-evk-u-boot.dtsi
@@ -3,7 +3,7 @@
  * Copyright 2019 NXP
  */
 
-&{/soc} {
+&{/soc@0} {
 	u-boot,dm-pre-reloc;
 	u-boot,dm-spl;
 };