I forgot to mention one thing, before you actually do it and reach a dead end… You must also patch the makefile in the
/arch/arm/boot/dts/your-machine-folder so it compiles your customized dts!
Other option is to apply the same .bbappend to the already existent dts.
The approach I mentioned creates a new one.
And don’t forget to add new dts name to the
KERNEL_DEVICETREES in local.conf or the machine configuration.
Your best bet in my opinion is to apply the .bbappend as presented but instead of creating a new one, patch the existent dtsi.
In your Linux environment, I recommend you to install
Meld, on which you cant put two files side-by-side and it can create a patch for you. You just need to modify the destination headers for something like