ectool: make boardName a non-package argument

src/platform/kevin/default.nix

@@ -88,6 +88,6 @@ in {
         '';
       });
 
-    ectool = final.nixpkgsOnBuildForHost.callPackage (import ../../util/ectool) { };
+    ectool = final.nixpkgsOnBuildForHost.callPackage (import ../../util/ectool { boardName = "kevin"; }) { };
   });
 }

src/util/ectool/default.nix

@@ -1,8 +1,10 @@
+{ boardName
+}:
+
 { lib
 , stdenv
 , pkg-config
 , fetchFromGitHub
-, boardName ? "kevin"
 }:
 
 let makeTarget = "build/${boardName}/util/ectool";