splitting parts of system config

- hardware-configuration.nix separated into kernel-winter.nix and
  filesystem-winter.nix
- kernel.nix split off into kernel-winter.nix

modules/system/kernel.nix

@@ -1,32 +1,14 @@
 { config, pkgs, ... }: {
-  powerManagement.cpuFreqGovernor = "ondemand";
   boot = {
-    loader = {
-      systemd-boot.enable = true;
-      efi.canTouchEfiVariables = true;
-      grub = {
-        enable = true;
-        efiSupport = true;
-        device = "nodev";
-      };
-    };
     blacklistedKernelModules = [ "uvcvideo" ];
     initrd = {
       includeDefaultModules = false;
-      kernelModules = [ "i915" ];
+      availableKernelModules = [ "ehci_pci" "ahci" "usbhid" "usb_storage" "sd_mod" "sdhci_pci" ];
     };
     kernel.sysctl = {
       "kernel.core_pattern" = "|/bin/false";
       "kernel.sysrq" = 1;
     };
-    kernelParams = [
-      "amdgpu.gpu_recovery=1"
-      "amdgpu.si_support=1"
-      "radeon.si_support=0"
-      "intel_pstate=passive"
-      "msr.allow_writes=on"
-    ];
-    kernelPackages = pkgs.lib.mkForce (pkgs.linuxPackagesFor pkgs.linux-lava);
   };
   zramSwap.enable = true;
 }