I did it already.
I checked the /boot/dtb/broadcom/ directory and I have 2 files
-rw-r--r--. 1 root root 12611 Mar 26 18:10 bcm2837-rpi-3-b.dtb
-rw-r--r--. 1 root root 12933 Mar 26 18:10 bcm2837-rpi-3-b-plus.dtb
I am running kernel 4.16.0-0.rc7.git0.1.fc28.aarch64 and Peter was talking about rc6?