gnu: python-pyside-2: Clarify the package inputs.

The module "PySide.PyQtUiTools" depends on "qttools-5", it should be an input,
not a native input.

libxml2, libxslt, clang-toolchain is only used by python-shiboken-2.

cmake-minimal is not used.

* gnu/packages/qt.scm (python-pyside-2): [inputs]: Remove libxml2, libxslt,
clang-toolchain. Add qttools-5.
[native-inputs]: Remove cmake-minimal, qttools-5.
[arguments]<#:phases>: Remove phase "set-clang-dir".

Signed-off-by: Marius Bakke <marius@gnu.org>

gnu/packages/qt.scm

@@ -3851,10 +3851,7 @@ (define-public python-pyside-2
     (source (package-source python-shiboken-2))
     (build-system cmake-build-system)
     (inputs
-     (list libxml2
-           libxslt
-           clang-toolchain
-           qtbase-5
+     (list qtbase-5
            qtdatavis3d
            qtdeclarative-5
            qtlocation
@@ -3866,6 +3863,7 @@ (define-public python-pyside-2
            qtsensors
            qtspeech
            qtsvg-5
+           qttools-5
            qtwebchannel-5
            qtwebengine-5
            qtwebsockets-5
@@ -3874,7 +3872,7 @@ (define-public python-pyside-2
     (propagated-inputs
      (list python-shiboken-2))
     (native-inputs
-     (list cmake-minimal python-wrapper qttools-5 which))
+     (list python-wrapper))
     (arguments
      (list
       #:tests? #f
@@ -3928,12 +3926,7 @@ (define-public python-pyside-2
                 (setenv "CXXFLAGS" (fold (lambda (dir paths)
                                            (string-append paths " -I" dir))
                                          ""
-                                         dirs)))))
-          (add-before 'configure 'set-clang-dir
-            (lambda* (#:key inputs #:allow-other-keys)
-              (let ((clang (assoc-ref inputs "clang-toolchain")))
-                (setenv "CLANG_INSTALL_DIR" clang)
-                #t))))))
+                                         dirs))))))))
     (home-page "https://wiki.qt.io/Qt_for_Python")
     (synopsis
      "The Qt for Python product enables the use of Qt5 APIs in Python applications")