Add the temporary fix for the cpu-throttling issue

See https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Power_management.2FThrottling_issues

lenovo/thinkpad/x1/6th-gen/default.nix

@@ -1,3 +1,4 @@
+{ config, pkgs, ... }:
 {
   imports = [
     ../.
@@ -17,4 +18,41 @@
 START_CHARGE_THRESH_BAT0=75
 STOP_CHARGE_THRESH_BAT0=80
 '';
+
+  # Temporary fix for cpu throttling issues visible in the kernel log
+  # (journalctl -k) by setting the same temperature limits used by
+  # Window$
+  # See https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Power_management.2FThrottling_issues
+  systemd.services.cpu-throttling = {
+    enable = true;
+    description = "Sets the offset to 3 °C, so the new trip point is 97 °C";
+    documentation = [
+      "https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Power_management.2FThrottling_issues"
+    ];
+    path = [ pkgs.msr-tools ];
+    script = "wrmsr -a 0x1a2 0x3000000";
+    serviceConfig = {
+      Type = "oneshot";
+    };
+    wantedBy = [
+      "timers.target"
+    ];
+  };
+
+  systemd.timers.cpu-throttling = {
+    enable = true;
+    description = "Set cpu heating limit to 97 °C";
+    documentation = [
+      "https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_X1_Carbon_(Gen_6)#Power_management.2FThrottling_issues"
+    ];
+    timerConfig = {
+      OnActiveSec = 60;
+      OnUnitActiveSec = 60;
+      Unit = "cpu-throttling.service";
+    };
+    wantedBy = [
+      "timers.target"
+    ];
+  };
+
 }