Adding Power Management on Asus fa507nv

I personally own this laptop, I am running gnome and on sleep the
graphics always corrupt without fail, this setting has been the only way
to correct it.

asus/fa507nv/default.nix

@@ -39,6 +39,7 @@
   };
 
   hardware.nvidia = {
+    powerManagement.enable = true;
     modesetting.enable = lib.mkDefault true;
     open = lib.mkDefault false;
     nvidiaSettings = lib.mkDefault true;