I have a S905X, 2GB/16GB box.
I downloaded LibreELEC-S905.arm-8.2-8.1.4.img,gz and gxl_p212_2g,dtb, to my PC.
I used the LibreELEC USB-SD creator to install LibreELEC on my microSD.
All worked well and I have a dtb.img file installed in the LibreELEC partition on my microSD.
Do I need to do anything with the gxl_p212_2g,dtb that I downloaded?