dell/inspiron/7559: add + corresponding Skylake architecture configuration.

common/cpu/intel/skylake/cpu-only.nix

@@ -0,0 +1,5 @@
+{
+  imports = [
+    ../cpu-only.nix
+  ];
+}

common/cpu/intel/skylake/default.nix

@@ -0,0 +1,6 @@
+{
+  imports = [
+    ./cpu-only.nix
+    ../../../gpu/intel/skylake
+  ];
+}

common/gpu/intel/skylake/default.nix

@@ -0,0 +1,18 @@
+{ pkgs, ... }:
+
+{
+  imports = [ ../. ];
+
+  boot.kernelParams = [
+    "i915.enable_guc=2"
+  ];
+
+  # VP9 decoding not supported when using intel-media-driver
+  # https://github.com/intel/media-driver/issues/1024
+  # NixOS Wiki recommends using the legacy intel-vaapi-driver with the hybrid codec over that one for Skylake.
+  # https://wiki.nixos.org/wiki/Accelerated_Video_Playback
+  hardware.intelgpu = {
+    vaapiDriver = "intel-vaapi-driver";
+    enableHybridCodec = true;
+  };
+}