common/gpu/intel: Make initrd - i915 an option

common/gpu/intel/default.nix

@@ -1,8 +1,17 @@
 { config, lib, pkgs, ... }:
 
 {
-  boot.initrd.kernelModules = [ "i915" ];
+  options.hardware.intelgpu.loadInInitrd = lib.mkEnableOption (lib.mdDoc
+    "loading `i195` kernelModule at stage 1. (Add `i915` to `boot.initrd.kernelModules`)"
+  ) // {
+    default = true;
+  };
 
+  config = lib.mkMerge [
+    (lib.mkIf config.hardware.intelgpu.loadInInitrd { 
+      boot.initrd.kernelModules = [ "i915" ]; 
+    })
+    {
       environment.variables = {
         VDPAU_DRIVER = lib.mkIf config.hardware.opengl.enable (lib.mkDefault "va_gl");
       };
@@ -13,3 +22,5 @@
         intel-media-driver
       ];
     }
+  ];
+}