Add nixpad configuration

The initial step of grouping lemp11 and t490 configuration, inspired by
https://github.com/mkellyxp/nixbook.

hosts/t490/configuration.nix

@@ -17,6 +17,8 @@
 
   desktop.dconf.enable = true;
 
+  nixpad.enable = true;
+
   boot = {
     loader = {
       systemd-boot = {
@@ -35,6 +37,4 @@
   '';
 
   networking.networkmanager.enable = true;
-
-  system.autoUpgrade.enable = true;
 }

hosts/t490/services/default.nix

@@ -26,10 +26,5 @@
     throttled.enable = true;
     thermald.enable = true;
     upower.enable = true;
-
-    xserver = {
-      desktopManager.cinnamon.enable = true;
-      displayManager.lightdm.enable = true;
-    };
   };
 }