Split xeon specific configuration from base

To accomodate the raccoon knights workstation, some of the configuration
pulled by m/common/main.nix has to be removed. To solve it, the xeon
specific parts are placed into m/common/xeon.nix and only the common
configuration is at m/common/base.nix.

Reviewed-by: Aleix Roca Nonell <aleix.rocanonell@bsc.es>

m/raccoon/configuration.nix

@@ -0,0 +1,32 @@
+{ config, pkgs, lib, modulesPath, ... }:
+
+{
+  imports = [
+    ../common/base.nix
+  ];
+
+  # Don't install Grub on the disk yet
+  boot.loader.grub.device = "nodev";
+
+  networking = {
+    hostName = "raccoon";
+    # Only BSC DNSs seem to be reachable from the office VLAN
+    nameservers = [ "84.88.52.35" "84.88.52.36" ];
+    defaultGateway = "84.88.51.129";
+    interfaces.eno0.ipv4.addresses = [ {
+      address = "84.88.51.152";
+      prefixLength = 25;
+    } ];
+  };
+
+  # Configure Nvidia driver to use with CUDA
+  hardware.nvidia.package = config.boot.kernelPackages.nvidiaPackages.production;
+  hardware.opengl = {
+    enable = true;
+    driSupport = true;
+    setLdLibraryPath = true;
+  };
+  nixpkgs.config.allowUnfree = true;
+  nixpkgs.config.nvidia.acceptLicense = true;
+  services.xserver.videoDrivers = [ "nvidia" ];
+}