surface: Add powerManagement

modules/hardware/surface-pro6.nix

@@ -16,6 +16,12 @@ in {
     [Config]
     BlockOnPalm = true
   '';
+
+  powerManagement = {
+    enable = true;
+    cpuFreqGovernor = "powersave";
+  };
+  hardware.video.hidpi.enable = true;
   
   systemd.services.iptsd = {
     description = "Userspace daemon for Intel Precise Touch & Stylus";