Apply hifiberry-digi-pro.dtbo overlay from nixpkgs

hosts/pi/default.nix

@@ -6,17 +6,20 @@
     ../server.nix
   ];
 
-  networking.hostName = "pi";
-  networking.hostId = "";
+  networking.hostId = "731d1660";
 
   hardware = {
     raspberry-pi."4" = {
       apply-overlays-dtmerge.enable = true;
+      audio = false;
       fkms-3d.enable = true;
     };
     deviceTree = {
       enable = true;
       filter = "*rpi-4-*.dtb";
+      overlays = [
+        { name = "hifiberry-digi-pro"; dtboFile = "${pkgs.device-tree_rpi.overlays}/hifiberry-digi-pro.dtbo"; }
+      ];
     };
   };
 

hosts/pi/hardware-configuration.nix

@@ -5,11 +5,6 @@
     <nixos-hardware/raspberry-pi/4>
   ];
 
-  boot.loader.raspberryPi.firmwareConfig = ''
-    dtoverlay=vc4-kms-v3d,noaudio
-    dtoverlay=hifiberry-digi-pro
-  '';
-
   fileSystems = {
     "/" = {
       device = "/dev/disk/by-label/NIXOS_SD";