How to apply a device tree blob overlay on MSC SM2S IMX8PLUS

I try to apply a device tree blob (overlay-hdmi.dtb provided in the build output) with UBOOT on an AVNET MSC SM2S IMX8PLUS system with QT5 following the UBOOT instructions to activate the HDMI interface.

Unfortunately this does not work as expected. I receive the following message line during the boot process.

[    0.000000] Kernel command line: console=ttymxc1,115200 root=/dev/mmcblk1p2 rootwait rw dtb-module=msc-sm2s-imx8mp-24N0600I-module.dtb dtb-overlay=undefined loglevel=7

Any idea how to set the DTB overlay properly to activate the HDMI interface?

I followed the simple steps below. No need for using the UBOOT instructions.

1. setenv fdt_overlay overlay-hdmi.dtb

2. set the display info with the proper interface and resolution

   setenv displayinfo 'video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24'

3. saveenv

4. boot

Afterwards I recognized that the Kernel command line in the boot process changed.

[    0.000000] Kernel command line: console=ttymxc1,115200 root=/dev/mmcblk1p2 rootwait rw dtb-module=msc-sm2s-imx8mp-24N0600I-module.dtb dtb-overlay=overlay-hdmi.dtb loglevel=7

Furthermore the monitor connected via HDMI and displayed the expected output.