common: Move Intel generation-specific config from cpu to gpu

These modules only included gpu configuration, so belong in that
location.

common/gpu/intel/tiger-lake/default.nix

@@ -0,0 +1,12 @@
+{ config, lib, ... }:
+{
+  imports = [ ../. ];
+  config = lib.mkMerge [
+    (lib.mkIf (lib.versionAtLeast config.boot.kernelPackages.kernel.version "6.8") {
+      hardware.intelgpu.driver = "xe";
+    })
+    (lib.mkIf (config.hardware.intelgpu.driver == "i915") {
+      boot.kernelParams = [ "i915.enable_guc=3" ];
+    })
+  ];
+}