localtime: install systemd serice and polkit rules

- Use the right variables and `make install` to ensure all products are
installed.
- Remove unneeded build inputs: we don't need systemd or polkit to
install the service or polkit rules.

pkgs/tools/system/localtime/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, systemd, polkit, fetchFromGitHub, buildGoPackage, m4}:
+{ stdenv, fetchFromGitHub, buildGoPackage, m4 }:
 
 buildGoPackage rec {
   name = "localtime-2017-11-07";
@@ -11,18 +11,17 @@ buildGoPackage rec {
   };
   goPackagePath = "github.com/Stebalien/localtime";
 
-  buildInputs = [ systemd polkit m4 ];
+  buildInputs = [ m4 ];
 
-  makeFlags = [ "PREFIX=$(out)" ];
+  makeFlags = [ "PREFIX=$(out)" "BINDIR=$(bin)/bin" ];
 
   buildPhase = ''
     cd go/src/${goPackagePath}
-    make localtimed
+    make $makeFlags
   '';
 
   installPhase = ''
-    mkdir -p $bin/bin
-    install -Dm555 localtimed $bin/bin
+    make install $makeFlags
   '';
 
   meta = with stdenv.lib; {