[Altair] Disable device auto-sleep for xpadneo/bluetooth.

system/hosts/altair/hardware-configuration.nix

@@ -34,9 +34,11 @@
     extraModulePackages = [ ];
 
     # disable_ertm is required for xpadneo to connect properly and establish a
-    # data connection.
+    # data connection.  enable_autosuspend is to prevent Linux from putting the
+    # BT radio to sleep and causing a disconnect.
     extraModprobeConfig = ''
       options bluetooth disable_ertm=1
+      options btusb enable_autosuspend=0
     '';
   };