Add elara sas specialisation

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/elara/hardware/default.nix

@@ -5,4 +5,15 @@
     "uas"
     "sd_mod"
   ];
+
+  services.tlp.settings.DISK_DEVICES = "sda";
+
+  # By default, this host runs on an external SSD attached to eirene...
+  imports = [ ../../eirene/hardware ];
+
+  # ...but it can also run attached to a SAS-provided laptop.
+  specialisation.sas.configuration = {
+    disabledModules = [ ../../eirene/hardware ];
+    imports = [ ./sas ];
+  };
 }